View source for U.S. Route 321

{{short description|Highway in the United States}}
{{Use American English|date=April 2025}}
{{Use mdy dates|date=February 2022}}
{{Infobox road
|country=USA
|type=US
|route=321
|map={{maplink|frame=yes|plain=yes|frame-align=center|frame-width=290|frame-height=290|type=line|from=U.S. Route 321.map}}
|map_custom=yes
|map_notes=US&nbsp;321 highlighted in red
|length_mi=516.9
|length_ref=<ref name=google-sc>{{google maps|url=https://maps.google.com/maps?saddr=Deerfield+Rd&daddr=33.15141,-81.1925771+to:33.9963925,-81.0442315+to:34.085916,-81.0255667+to:34.6353403,-81.1852527+to:US-321+N&hl=en&ll=33.779147,-80.084839&spn=3.976305,7.13562&sll=34.067023,-80.985546&sspn=0.123857,0.222988&geocode=FRCd7AEdmMgq-w%3BFbLZ-QEdfxkp-ylJ1ZARFhX5iDEgin1Xp0VnZg%3BFWi-BgId-Vwr-ykDVn1MMLv4iDHpdzk6YgYHow%3BFRwcCAId4qUr-ynhPclD0aX4iDHqjmVd5__BAw%3BFUx-EAIdHDYp-ymhVq7vH0JWiDHmeBuQdWWqlA%3BFdl2GAIdNv8o-w&mra=dpe&mrsp=3&sz=13&via=1,2,3,4&t=p&z=8|title=U.S. Route 321 in South Carolina|access-date=December 22, 2013}}</ref><ref name=google-nc>{{google maps|url=https://maps.google.com/maps?saddr=US-321+N%2FYork+Hwy&daddr=36.2220457,-81.6957428+to:US-321+N&hl=en&ll=35.710838,-81.03241&spn=1.942389,3.56781&sll=36.180562,-81.574173&sspn=0.241368,0.445976&geocode=Fbt4GAIdSwAp-w%3BFV20KAIdAmwh-ynNiN6tp_BQiDG5Z_MNvyc7pw%3BFbSiKQIdx_0d-w&mra=dpe&mrsp=1&sz=12&via=1&t=p&z=9|title=U.S. Route 321 in North Carolina|access-date=December 22, 2013}}</ref><ref name=google-tn>{{google maps|url=https://maps.google.com/maps?saddr=TN-159+W%2FUS-321+N&daddr=36.2287533,-82.6643001+to:35.7163599,-83.5033068+to:35.7957342,-83.5918262+to:35.7380705,-84.1925955+to:TN-73+W%2FTN-73+Scenic+W%2FTN-95+N%2FUS-321+S%2FUS-321+Scenic+N&hl=en&ll=35.802222,-83.048401&spn=1.94016,3.56781&sll=36.209377,-82.53685&sspn=0.482557,0.891953&geocode=FWajKQIdJ_wd-w%3BFZHOKAIdlKQS-ykdPsWfQ1taiDG70eX35vaugg%3BFQf9IAIdNtcF-ynBOXiUdFZZiDEwDgQv-0P-MA%3BFRYzIgIdbn0E-ykDUwubff9biDGiUXanPuttnQ%3BFdZRIQIdrVL7-ik9f3qmhoFeiDE4cU95FqGE5Q%3BFUlpIwIdN1D5-g&mra=dpe&mrsp=1&sz=11&via=1,2,3,4&t=p&z=9|title=U.S. Route 321 in Tennessee|access-date=December 22, 2013}}</ref>
|tourist=[[File:South Carolina Scenic Byway.svg|20px|alt=|link=]] Western York Scenic Byway
|established=1931
|direction_a=South
|terminus_a={{jct|state=SC|US|17}} in [[Hardeeville, South Carolina|Hardeeville, SC]]
|junction={{plainlist|
*{{Jct|state=SC|I|26}} in [[Cayce, South Carolina|Cayce, SC]]
*{{Jct|state=SC|I|20}} in [[Columbia, South Carolina|Columbia, SC]]
*{{Jct|state=NC|I|85}} in [[Gastonia, North Carolina|Gastonia, NC]]
*{{Jct|state=NC|I|40}} in [[Hickory, North Carolina|Hickory, NC]]
*{{Jct|state=TN|I|26|US|19W|US|23}} in [[Johnson City, Tennessee|Johnson City, TN]]
*{{Jct|state=TN|I|40}} in [[Newport, Tennessee|Newport, TN]]
*{{Jct|state=TN|I|75}} in [[Lenoir City, Tennessee|Lenoir City, TN]]
}}
|direction_b=North
|terminus_b={{jct|state=TN|I|40|TN|73|TN|95}} near Lenoir City, TN
|states=[[South Carolina]], [[North Carolina]], [[Tennessee]]
|counties='''SC:''' [[Jasper County, South Carolina|Jasper]], [[Hampton County, South Carolina|Hampton]], [[Allendale County, South Carolina|Allendale]], [[Bamberg County, South Carolina|Bamberg]], [[Orangeburg County, South Carolina|Orangeburg]], [[Lexington County, South Carolina|Lexington]], [[Richland County, South Carolina|Richland]], [[Fairfield County, South Carolina|Fairfield]], [[Chester County, South Carolina|Chester]], [[York County, South Carolina|York]]<br />'''NC:''' [[Gaston County, North Carolina|Gaston]], [[Lincoln County, North Carolina|Lincoln]], [[Catawba County, North Carolina|Catawba]], [[Burke County, North Carolina|Burke]], [[Caldwell County, North Carolina|Caldwell]], [[Watauga County, North Carolina|Watauga]], [[Avery County, North Carolina|Avery]]<br />'''TN:''' [[Johnson County, Tennessee|Johnson]], [[Carter County, Tennessee|Carter]], [[Washington County, Tennessee|Washington]], [[Greene County, Tennessee|Greene]], [[Cocke County, Tennessee|Cocke]], [[Sevier County, Tennessee|Sevier]], [[Blount County, Tennessee|Blount]], [[Loudon County, Tennessee|Loudon]]
|spur_type=US
|spur_of=21
|browse={{sc browse|previous_type=SC|previous_route=319|route=[[List of numbered highways in South Carolina|SC]]|next_type=SC|next_route=322}}<br />{{nc browse|previous_type=US|previous_route=311|route=[[North Carolina State Highways|NC]]|next_type=NC|next_route=343}}<br />{{tn browse|previous_type=Sec|previous_route=320|route=[[List of state routes in Tennessee|TN]]|next_type=Sec|next_route=321}}
}}
'''U.S. Route&nbsp;321''' ('''US&nbsp;321''') is a spur of [[U.S. Route 21]].  It runs for {{convert|516.9|mi|km}} from [[Hardeeville, South Carolina]] to [[Lenoir City, Tennessee]]; with both serving as southern termini. It reaches its northernmost point at [[Elizabethton, Tennessee]], just northeast of [[Johnson City, Tennessee|Johnson City]]. Because of its unusual "north&ndash;south&ndash;north" routing, U.S. Route 321 intersects both [[Interstate 40 in North Carolina|Interstate 40]] and [[U.S. Route 70 in North Carolina|U.S. Route 70]] three separate times. The highway serves different roles in each state:  An alternate route to interstates in South Carolina, a major highway in [[North Carolina]], and a scenic route in Tennessee.

==Route description==

{{lengths table}}
|-
|SC
|217.2
|349.5
|-
|NC
|105.5
|169.8
|-
|TN
|194.2
|312.5
|-
|Total
|516.9
|831.8
|}

===South Carolina===
US 321 provides direct access between [[Savannah, Georgia|Savannah]] and [[Columbia, South Carolina|Columbia]], serving as an alternate to [[Interstate 95]] and [[Interstate 26]].  Starting in Hardeeville, US 321  as a mostly 2 lane highway goes through sparsely populated areas and small towns including [[Estill, South Carolina|Estill]], [[Fairfax, South Carolina|Fairfax]], and [[Denmark, South Carolina|Denmark]], heading in a rather straight and northward direction into the Columbia area, widening to a 5 lane highway right after [[Neeses, South Carolina|Neeses]], then narrowing down to a 2 lane highway right after the town of [[North, South Carolina|North]] and widening to a 5 lane highway again after [[Swansea, South Carolina|Swansea]] and staying that way until it merges with its parent route [[U.S. Route 21 in South Carolina|US 21]] in Dixiana.  In Columbia, the route stays concurrent with US 21 through [[Cayce, South Carolina|Cayce]], over the [[Congaree River]] on the Blossom Street Bridge, turning left onto Huger Street, right onto Elmwood Avenue, and left onto North Main Street.  The roads separate at Hyatt Park, with US 321 staying west of [[Interstate 77 in South Carolina|I-77]] and US 21 north of Columbia.  The route goes through to communities of [[Winnsboro, South Carolina|Winnsboro]], [[Chester, South Carolina|Chester]], [[York, South Carolina|York]], and [[Clover, South Carolina|Clover]] before entering North Carolina at Bowling Green.

===North Carolina===
US 321 is an important route in [[Western North Carolina]]. It provides an alternative north&ndash;south route to [[Interstate 77 in North Carolina|I-77]], which passes through a busy metropolitan area, and [[U.S. Route 221 in North Carolina|US 221]], which is more twisty drive up the [[Appalachian Mountains|Appalachians]]. Travelers from South Carolina who are going to points west of [[Charlotte, North Carolina|Charlotte]] and want to avoid the traffic of I-77 may choose to enter the state on US 321.

The highway traverses through seven counties: [[Gaston County, North Carolina|Gaston]], [[Lincoln County, North Carolina|Lincoln]], [[Catawba County, North Carolina|Catawba]], [[Burke County, North Carolina|Burke]], [[Caldwell County, North Carolina|Caldwell]], [[Watauga County, North Carolina|Watauga]], and [[Avery County, North Carolina|Avery]]. US 321 has six control cities: [[Gastonia, North Carolina|Gastonia]], [[Lincolnton, North Carolina|Lincolnton]], [[Hickory, North Carolina|Hickory]], [[Lenoir, North Carolina|Lenoir]], [[Blowing Rock, North Carolina|Blowing Rock]], and [[Boone, North Carolina|Boone]].

US 321 is a multilane highway beginning at the state line. After {{convert|7|mi|km}}, it enters the [[Gastonia, North Carolina|Gastonia]] area. Traffic on northbound 321 through Gastonia is generally not as heavy as traffic on southbound 321 north of [[Interstate 85 in North Carolina|I-85]], where it may back up for a couple of miles as drivers wait to turn onto I-85. The state completed a new interchange with I-85 in 2021 which has southbound 321 cross over 321NB at a stoplight just north of I-85. The traffic now enters I-85 northbound with a flyunder entrance ramp over a former railroad right-of-way.<ref>{{cite web|url=https://www.ncdot.gov/news/press-releases/Pages/2021/2021-02-25-gastonia-interstate-85-interchange.aspx|title=NCDOT: Contractors Complete New Interchange at I-85 and U.S. 321 in Gaston County|last=webmaster|website=www.NCDOT.gov|access-date=11 November 2024}}</ref>

The road becomes a freeway at C. Grier Beam Boulevard in Gastonia, just south of [[North Carolina Highway 275|NC 275]]/[[North Carolina Highway 279|NC 279]]. It remains a freeway until just north of its junction with [[U.S. Route 70 in North Carolina|US 70]] in Hickory. The freeway bypasses a number of cities that the old US 321 route once passed through. Today, US 321 Business follows the original {{convert|38|mi|km|adj=on}} route, which serves [[Maiden, North Carolina|Maiden]], [[Newton, North Carolina|Newton]], and [[Conover, North Carolina|Conover]], but the freeway is a more direct route to the mountains, and the business route is generally used by local traffic only.

Traffic is usually heavy between [[Hickory, North Carolina|Hickory]] and [[Lenoir, North Carolina|Lenoir]]. The [[North Carolina Department of Transportation]] (NCDOT) has a long-term plan to widen the road to six lanes, which is expected to begin after 2020.<ref>{{cite web|url=https://www.ncdot.gov/projects/us321widening/|title=NCDOT: U.S. 321 Widening from Hickory to Lenoir|last=webmaster|website=www.NCDOT.gov|access-date=January 17, 2018}}</ref>

North of Lenoir, US 321 is a four-lane divided highway, continuing up the steep escarpment of the [[Blue Ridge Mountains]]. Until early 2018, the road was a narrow two-lane highway from near [[Patterson, North Carolina|Patterson]] through [[Blowing Rock, North Carolina|Blowing Rock]]. Work on this area continued for much of the first two decades of the 21st century. The widening of US 321 through Blowing Rock was and continues to be seen as a controversial project. Many residents of the town felt that a four-lane highway would destroy the character of the small town, and they proposed several bypass alternatives. NCDOT selected the widening as its preferred alternative, but added several features such as underground utilities, sidewalks, landscaping, and rock walls to make the widening more palatable to the residents opposed to it.<ref>{{cite web |url=http://www.ncdot.org/projects/BlowingRock321/|title=NCDOT: US 321 Improvements, Blowing Rock|access-date=October 22, 2010}}</ref> These features were not present on the two-lane highway that was replaced.  The final portion of the widening project, at the steepest part of the road just south of Blowing Rock, began in 2012 and was completed in 2018.<ref>{{cite web|url=https://www.hcpress.com/front-page/u-s-321-widening-project-blowing-rock-continues-hopefully-finished-winter.html|title=U.S. 321 Widening Project in Blowing Rock Continues, Hopefully Finished by Winter - High Country Press|website=www.HCPress.com|access-date=January 17, 2018}}</ref> Some landscaping work remains which will commence in Fall 2018 as its own project, constructed separately for beautification of the route through town.

North of Blowing Rock, US 321 is already a highway of four lanes up to King Street in [[Boone, North Carolina|Boone]]; thus, US 321 is a four-lane highway from the South Carolina state line to downtown Boone. Currently,{{When|date=January 2018}} US 321 meets [[U.S. Route 421 in North Carolina|US 421]] at King Street and overlaps it over King Street to leave town to the west. NCDOT project R-2615 is proposed to widen the US 321/421 concurrency from this junction to their junction near [[Vilas, North Carolina|Vilas]], although this project is currently unfunded.<ref>{{cite web |url=http://www.ncdot.org/planning/development/TIP/TIP/Trans/maps/R2615.html|title=NCDOT: TIP}}</ref> There is a feasibility study (FS-0511A) in progress{{When|date=January 2018}} to examine the possibility of widening US 321 from the junction near Vilas to the Tennessee state line. If both of these projects were completed, then US 321 would be a four-lane highway through the entire state.

===Tennessee===
[[Image:Parrotsville Tennessee US 321 John Sevier Highway.jpg|thumb|250px|right|Former portion of US 321 in [[Parrottsville, Tennessee]], facing south before it was rerouted.]]
As it crosses into Tennessee, US 321 enters the [[Cherokee National Forest]], and continues westward through the rugged valley between Pond Mountain on the south and [[Watauga Lake]] on the north.  The highway passes numerous campgrounds, boat launches, and other lake-related recreational areas as it winds its way along the shores of the lake.  South of [[Butler, Tennessee|Butler]], the highway joins [[Tennessee State Route 67|SR 67]], which enters from the [[Mountain City, Tennessee|Mountain City]] area to the northeast.  The [[Appalachian Trail]] crosses US 321 at its intersection with Shook Gap Road, just before the highway exits the national forest.  At [[Hampton, Tennessee|Hampton]], US 321 intersects [[U.S. Route 19E|US 19E]], and the two highways run concurrently northward into [[Elizabethton, Tennessee|Elizabethton]].

US 321 inverts directions in Elizabethton: the road is designated as southbound in both directions driving away from its intersection with US 19E.<ref>{{cite web |url=http://www.millenniumhwy.net/interestingsigns/tn/US321-Tennessee/|title=The US 321 Directional Change|access-date=October 22, 2010}}</ref> It is conterminous with US 11E through portions of [[Washington County, Tennessee|Washington]] and [[Greene County, Tennessee|Greene]] counties.  In [[Greeneville, Tennessee|Greeneville]], the highway continues south into [[Cocke County, Tennessee|Cocke County]]. At the Cocke-Greene County line US 321 becomes a four-laned divided highway and bypasses [[Parrottsville, Tennessee|Parrottsville]]. The four-lane section ends just before US 321's junction with [[Tennessee State Route 160|SR 160]] and crossing [[Interstate 40 in Tennessee|I-40]] at [[Newport, Tennessee|Newport]].

[[File:Maryville-US321-light-trails-tn1.jpg|right|250px|thumb|US 321 (Lamar Alexander Parkway) in [[Maryville, Tennessee|Maryville]]]]

The stretch of US 321 from Newport south to [[Cosby, Tennessee|Cosby]] and southwest through [[Pittman Center, Tennessee|Pittman Center]] to [[Gatlinburg, Tennessee|Gatlinburg]] parallels the northern boundary of the [[Great Smoky Mountains National Park]] and is quite scenic. From a point between Newport and Cosby to the intersection with the [[Little River Road]], it is concurrent with [[Tennessee State Route 73|SR 73]]. In [[Pigeon Forge, Tennessee|Pigeon Forge]], concurrent with [[U.S. Route 441 in Tennessee|US 441]]/[[Great Smoky Mountains Parkway]], US 321 is a divided, multi-lane traffic-laden thoroughfare where it serves as the city's main route, lined with hotels, outlet malls and amusement facilities. Veering southwest of Pigeon Forge, the highway takes on a more rural character as it traverses [[Wears Valley, Tennessee|Wears Valley]], and narrows down to two lanes until its junction with [[Tennessee State Route 73 Scenic|SR 73 Scenic]] (the Little River Road) at the [[Townsend, Tennessee|Townsend]] entrance to the park. It is concurrent with SR 73 from this junction to its terminus. With the exception of a {{convert|3|mi|km|adj=on}} section between [[Townsend, Tennessee|Townsend]] and [[Maryville, Tennessee|Maryville]], the remaining portions of the highway through [[Blount County, Tennessee|Blount County]] are a minimum of four lanes and usually a divided highway. Once the highway reaches [[Fort Loudon Dam]] in [[Loudon County, Tennessee|Loudon County]], it crosses the [[Tennessee River]] via a bridge, completed in 2017, southeast of the dam then intersects with [[U.S. Route 11 in Tennessee|US 11]] in [[Lenoir City, Tennessee|Lenoir City]]. US 321 has a [[wrong-way concurrency]] with [[Tennessee State Route 95|SR 95]] from a point several miles south of Lenoir City (near [[Greenback, Tennessee|Greenback]]) to its terminus at [[Interstate 40 in Tennessee|I-40]].  In the northern part of Lenoir City, US 321 intersects [[Interstate 75 in Tennessee|I-75]] and [[U.S. Route 70|US 70]] before reaching I-40.  Beyond I-40, the road continues northward to [[Oak Ridge, Tennessee|Oak Ridge]] as the two-lane SR 95.

US 321 is a four-lane semi-divided thoroughfare from I-40 and I-75 to the Great Smoky Mountains National Park, except for the {{convert|3|mi|km|adj=on}} stretch near Walland.

==History==
{{Expand section|date=October 2017}}
{{Clear}}

===North Carolina Highway 17===
{{Infobox road small
|state=NC
|type=NC 1945
|route=17
|location=[[Propst Crossroads, North Carolina|Propst Crossroads]]&ndash;[[Boone, North Carolina|Boone, NC]]
|formed=1921
|deleted=1934
|length_mi=55.9
|length_ref=<ref>{{google maps|url=https://maps.google.com/maps?saddr=NC-127+N&daddr=35.726668,-81.3358809+to:35.7523683,-81.3690522+to:35.7851343,-81.4163576+to:35.8124258,-81.4592721+to:35.8828436,-81.5202418+to:35.9160896,-81.5397294+to:36.1288711,-81.6793553+to:Hardin+St&hl=en&ll=35.907962,-81.316681&spn=0.958807,1.783905&sll=35.73871,-81.351786&sspn=0.030027,0.055747&geocode=FYqeHwIdlE4m-w%3BFUwlIQIduOkm-ymHuVDB1jFRiDHjvqw17bJbZw%3BFbCJIQIdJGgm-yk_C0rxuy9RiDFwvFDO1XVPvw%3BFa4JIgIdW68l-ylJwIOi9yVRiDH7bp1C5Om39A%3BFUl0IgIduAcl-yn3biJ7RiZRiDEoFJfIhNLgpg%3BFVuHIwIdjxkk-ylbvDOiVt9QiDGNfqRTXd0ZPg%3BFTkJJAIdb80j-ymFxxucDN9QiDHySCswPlzl9g%3BFWdIJwIdBawh-ymXKXs8Q-VQiDHACZApA96jDQ%3BFTmeKAIdYb4h-w&mra=mrv&via=1,2,3,4,5,6,7&t=p&z=10|title=North Carolina Highway 17|access-date=May 18, 2014}}</ref>
}}
'''North Carolina Highway 17''' ('''NC&nbsp;17''') was an original state highway that traversed from [[Hickory, North Carolina|Hickory]] to Boone, through [[Granite Falls, North Carolina|Granite Falls]], [[Hudson, North Carolina|Hudson]], [[Lenoir, North Carolina|Lenoir]] and [[Blowing Rock, North Carolina|Blowing Rock]]. In 1930, it was extended south on new primary routing to [[North Carolina Highway 113|NC&nbsp;113]], in Propst Crossroads; also same year, US&nbsp;321 was established in the state and overlapped NC&nbsp;17 between Hickory and Boone.<ref>{{cite map |publisher= North Carolina Department of Transportation |url= http://dotw-xfer01.dot.state.nc.us/imgdot/DOTStateTravelMapHistoric/STM1930.pdf |format= PDF |title= State Highway System of North Carolina |cartography= NCDOT |year= 1930 |access-date= May 18, 2014}}</ref>  In 1934, NC&nbsp;17 was decommissioned, with US&nbsp;321 taking all north of Hickory and [[North Carolina Highway 96|NC&nbsp;96]] taking all south.<ref>{{cite map |publisher= North Carolina Department of Transportation |url= http://dotw-xfer01.dot.state.nc.us/imgdot/DOTStateTravelMapHistoric/STM1940.pdf |format= PDF |title= North Carolina Primary Highway System |cartography= NCDOT |year= 1940 |access-date= May 18, 2014}}</ref>
{{Clear}}

===North Carolina Highway 155===
{{Infobox road small
|state=NC
|type=NC
|route=155
|location=[[Dallas, North Carolina|Dallas]]&ndash;[[Conover, North Carolina|Conover, NC]]
|formed=1994
|deleted=1999
|length_mi=29.4
|length_ref=<ref>{{google maps|url=https://maps.google.com/maps?saddr=State+Rd+155%2FUS-321+BUS+N&daddr=35.3355501,-81.2029698+to:35.389441,-81.2094389+to:35.45703,-81.2424383+to:35.5129622,-81.2384353+to:35.6187407,-81.2185295+to:Northwest+Blvd&hl=en&ll=35.527756,-81.153946&spn=0.481698,0.891953&sll=35.69045,-81.219306&sspn=0.030045,0.055747&geocode=FTHgGgIdUiUp-w%3BFX4tGwId5_Ao-yl7lC-dK8dWiDEo_byZtAGTaA%3BFQEAHAIdotco-ykvf1sUTcZWiDF2XWBqiVUfUw%3BFQYIHQIdulYo-ylh8Cc_0MhWiDFuMhsqc2_JHA%3BFYLiHQIdXWYo-ynJIP8K48tWiDF0WhKwcWel0A%3BFbR_HwIdH7Qo-ymzf1G-5zRRiDHB55pLZcSRig%3BFd2vIAId1pco-w&mra=dme&mrsp=6&sz=15&via=1,2,3,4,5&t=p&z=11|title=North Carolina Highway 155|access-date=May 18, 2014}}</ref>
}}
'''North Carolina Highway 155''' ('''NC&nbsp;155''') was established in 1994 following the old alignment of US&nbsp;321 as it was moved onto new four-lane [[controlled-access highway]].<ref>{{cite web |publisher= North Carolina Department of Transportation |url= https://connect.ncdot.gov/resources/safety/Route%20Changes/1994_10_18.pdf |title= Route Change (1994-10-18) |date= October 18, 1994 |access-date= May 18, 2014}}</ref>  From [[North Carolina Highway 275|NC&nbsp;275]]/[[North Carolina Highway 279|NC&nbsp;279]], in Dallas, it traversed north through [[High Shoals, North Carolina|High Shoals]] to [[Lincolnton, North Carolina|Lincolnton]].  Sharing a short concurrency with [[North Carolina Highway 150|NC&nbsp;150]] as it bypass the downtown area of Lincolnton, it continues north meeting with main US&nbsp;321, south of [[Maiden, North Carolina|Maiden]], continuing in concurrency through [[Newton, North Carolina|Newton]] and finally Conover, where it ended at [[U.S. Route 70 in North Carolina|US&nbsp;70]].  In 1999, the remainder of US&nbsp;321 was moved onto new freeway bypass west of Newton and Conover; at same time, NC&nbsp;155 was decommissioned and absorbed into US 321 Business.<ref name="1999 Route Change">{{cite web |publisher= North Carolina Department of Transportation |url= https://connect.ncdot.gov/resources/safety/Route%20Changes/1999_06_25.pdf |title= Route Change (1999-06-25) |date= June 25, 1999 |access-date= May 18, 2014}}</ref>
{{Clear}}

===North Carolina Highway 603===
{{infobox road small
|state=NC
|type=NC 1957
|route=603
|location=[[Tennessee|TN State Line]]&ndash;[[Sugar Grove, North Carolina|Sugar Grove, NC]]
|formed=1931
|deleted=1961
|length_mi=
|length_round=1
|length_ref=
}}
{{Empty section|date=January 2019}}
{{Clear}}

==Future==
In addition to the widening project, {{Citation needed span|date=December 2019|there have also been talks of a freeway-to-freeway connection with [[Interstate 85 in North Carolina|Interstate 85]] in [[Gastonia, North Carolina|Gastonia]] that would greatly relieve traffic flowing through the junction}}.  Currently, US&nbsp;321 is a surface road at the I-85 interchange, and is a limited access freeway a few hundred yards north.  To extend the freeway to I-85, the remaining at-grade intersections and traffic lights would have to be eliminated.

==Major intersections==
{{jcttop|state_col=state|length_ref=<br/><ref name=google-sc/><ref name=google-nc/><ref name=google-tn/>}}
{{SCint
|sspan=64
|county=Jasper
|cspan=5
|location=Hardeeville
|lspan=2
|mile=0.0
|road={{jct|state=SC|US|17|name1=Whyte Hardee Boulevard|city1=Ridgeland|location2=[[Savannah, Georgia|Savannah]]}}}}
{{SCint
|mile=0.5
|road={{jct|state=SC|SC|46|dir1=east|name1=Church Road}}
|notes=To Millstone Landing}}
{{SCint
|location=Tillman
|mile=12.5
|road={{jct|state=SC|SC|336|dir1=east|name1=Tillman Road|city1=Ridgeland}}}}
{{SCint
|location=Tarboro
|mile=19.8
|road={{jct|state=SC|US|601|dir1=north|name1=Cypress Branch Road|city1=Hampton}}
|notes=Southern terminus of US &nbsp;601}}
{{SCint
|location=Robertville
|mile=22.6
|road={{jct|state=SC|SC|462|name1=Gillson Branch Road|city1=Pineland}}}}
{{SCint
|county=Hampton
|cspan=5
|location=Garnett
|mile=25.6
|road={{Jct|state=SC|SC|119|dir1=south|name1=Clyo Road|location1=[[Clyo, Georgia|Clyo]]|location2=[[Springfield, Georgia|Springfield]]}}}}
{{SCint
|location=Scotia
|mile=30.7
|road={{jct|state=SC|SC|333|name1=Scotia-Furman Highway|city1=Furman}}}}
{{SCint
|location=Estill
|lspan=2
|type=concur
|mile=35.8
|road={{jct|state=SC|SC|3|dir1=south|name1=Third Street|city1=Lena}}
|notes=South end of SC&nbsp;3 overlap}}
{{SCint
|type=concur
|mile=36.0
|road={{jct|state=SC|SC|3|dir1=north|name1=Nixville Road|city1=Barnwell}}
|notes=North end of SC&nbsp;3 overlap}}
{{SCint
|location=none
|mile=40.4
|road={{jct|state=SC|SC|363|dir1=east|name1=Luray Highway|city1=Hampton}}
|notes=To [[Lake Warren State Park]]}}
{{SCint
|county=Allendale
|cspan=3
|location=Fairfax
|mile=49.9
|road={{jct|state=SC|US|278|name1=Allendale-Hampton Highway|city1=Allendale|city2=Hampton}}}}
{{SCint
|location=Sycamore
|mile=55.6
|road={{jct|state=SC|SC|641|name1=Confederate Highway|city1=Allendale}}}}
{{SCint
|location=Ulmer
|type=concur
|mile=59.9
|road={{jct|state=SC|US|301|dir1=south|name1=Burton's Ferry Highway|city1=Allendale}}
|notes=South end of US&nbsp;301 overlap}}
{{SCint
|county=Bamberg
|cspan=5
|location=none
|type=concur
|mile=61.9
|road={{jct|state=SC|US|301|dir1=north|name1=Main Highway|city1=Bamberg}}
|notes=North end of US&nbsp;301 overlap}}
{{SCint
|location=Olar
|mile=66.5
|road={{jct|state=SC|SC|64|name1=Low Country Road|city1=Barnwell}}}}
{{SCint
|location=Denmark
|type=concur
|mile=76.6
|road={{jct|state=SC|SC|70|dir1=south|name1=Hagood Street|city1=Barnwell}}
|notes=South end of SC&nbsp;70 overlap}}
{{SCint
|location=none
|mile=76.9
|road={{jct|state=SC|US|78|name1=Heritage Highway|city1=Bamberg|city2=Blackville}}}}
{{SCint
|location=none
|type=concur
|mile=77.3
|road={{jct|state=SC|SC|70|dir1=north|name1=Country Club Road|city1=Orangeburg}}
|notes=North end of SC&nbsp;70 overlap}}
{{SCint
|county=Orangeburg
|cspan=5
|location=Norway
|lspan=2
|type=concur
|mile=85.3
|road={{jct|state=SC|SC|332|dir1=east|name1=Cope Road|city1=Cope}}
|notes=East end of SC&nbsp;332 overlap}}
{{SCint
|type=concur
|mile=85.6
|road={{jct|state=SC|SC|332|SC|400|dir1=west|dir2=east|name2=Norway Road|city1=Springfield|city2=Orangeburg}}
|notes=West end of SC&nbsp;332 overlap}}
{{SCint
|location=Neeses
|lspan=2
|mile=90.9
|road={{jct|state=SC|SC|4|name1=Neeses Highway|city1=Springfield|city2=Orangeburg}}}}
{{SCint
|mile=91.4
|road={{jct|state=SC|SC|389|dir1=west|name1=Ninety Six Road|city1=Perry|city2=Wagener}}}}
{{SCint
|location=North
|mile=97.3
|road={{jct|state=SC|US|178|name1=North Highway|city1=Pelion|city2=Orangeburg}}}}
{{SCint
|county=Lexington
|cspan=10
|location=Swansea
|lspan=4
|mile=105.1
|road={{jct|state=SC|SC|3|dir1=south|name1=Whetstone Road|city1=Springfield|city2=Blackville|city3=Barnwell}}}}
{{SCint
|mile=105.9
|road={{jct|state=SC|SC|692|dir1=south|name1=Fifth Street|city1=Orangeburg}}
|notes=To Swansea High Football Stadium}}
{{SCint
|type=concur
|mile=106.1
|road={{jct|state=SC|SC|6|dir1=west|name1=Second Street|city1=Lexington}}
|notes=West end of SC&nbsp;6 overlap}}
{{SCint
|type=concur
|mile=106.2
|road={{jct|state=SC|SC|6|dir1=east|name1=First Street|city1=St. Matthews}}
|notes=East end of SC&nbsp;6 overlap}}
{{SCint
|location=none
|type=concur
|mile=117.7
|road={{jct|state=SC|US|21|US|176|dir1=south|dir2=east|name2=Charleston Highway|city1=Orangeburg}}
|notes=South end of US&nbsp;21 and east end of US&nbsp;176 overlap}}
{{SCint
|location=Cayce
|lspan=3
|mile=120.2
|road={{jct|state=SC|I|77|to1=to|dir1=north|road|Fish Hatchery Road|location1=[[Charlotte, North Carolina|Charlotte]]}}}}
{{SCint
|mile=120.6
|road={{jct|state=SC|I|26|city1=Charleston|city2=Spartanburg}}}}
{{SCint
|mile=121.8
|road={{jct|state=SC|SC|2|dir1=north|name1=Frink Road}}}}
{{SCint
|location=West Columbia
|lspan=2
|mile=123.3
|road={{jct|state=SC|SC|302|dir1=south|name1=Airport Boulevard|city1=Aiken|location2=[[Columbia Metropolitan Airport]]}}}}
{{SCint
|mile=125.0
|road={{jct|state=SC|SC|2|name1=State Street}}}}
{{SCint
|county=Richland
|cspan=10
|location=Columbia
|lspan=10
|mile=
|road={{jct|state=SC|SC-Truck|48|dab1=Columbia|dir1=east|name1=Blossom Street east / [[U.S. Route 21 Connector (Columbia, South Carolina)|US&nbsp;21 Conn.]] east / [[U.S. Route 76 Connector (Columbia, South Carolina)|US&nbsp;76 Conn.]] east}}
|notes=Western terminus of US&nbsp;21 Conn., the western segment of US&nbsp;76 Conn., SC&nbsp;48 Truck, and Blossom Street; US&nbsp;21, US&nbsp;176, and US&nbsp;321 turn left off of Blossom Street onto Huger Street.
}}
{{SCint
|mile=126.5
|road={{jct|state=SC|US|1|US|378|name2=Gervais Street}}
|notes=To [[South Carolina State House]]}}
{{SCint
|mile=126.8
|road={{jct|state=SC|SC|12|name1=Hampton/Tylor Streets}}
|notes=To [[Finlay Park]] and [[Columbia Museum of Art]]}}
{{SCint
|type=concur
|mile=127.4
|road={{jct|state=SC|I|126|US|76|dir1=west|dir2=west|city1=Greenville|city2=Spartanburg}}
|notes=West end of US&nbsp;76 overlap}}
{{SCint
|type=concur
|mile=128.0
|road={{jct|state=SC|US|76|dir1=east|name1=Elmwood Avenue}}
|notes=East end of US&nbsp;76 overlap}}
{{SCint
|type=concur
|mile=128.6
|road={{jct|state=SC|US|176|dir1=west|name1=River Drive}}
|notes=West end of US&nbsp;176 overlap}}
{{SCint
|mile=129.2
|road={{jct|state=SC|SC|16|name1=Sunset Drive}}}}
{{SCint
|mile=129.8
|road={{jct|state=SC|SC|215|dir1=north|name1=Montichello Road}}
|notes=To [[Columbia International University]]}}
{{SCint
|type=concur
|mile=130.8
|road={{jct|state=SC|US|21|dir1=north|name1=Main Street}}
|notes=North end of US&nbsp;21 overlap; [[Columbia College (South Carolina)|Columbia College]] at intersection}}
{{SCint
|mile=132.2
|road={{jct|state=SC|I|20|city1=Florence|location2=[[Augusta, Georgia|Augusta]]}}}}
{{SCint
|county=Fairfield
|cspan=5
|location=none
|mile=151.2
|road={{jct|state=SC|SC|269|dir1=south|name1=Hinnants Store Road|locaiton1=[[Fairfield County Airport (South Carolina)|Fairfield County Airport]]}}}}
{{SCint
|location=Winnsboro Mills
|lspan=2
|type=concur
|mile=152.4
|road={{jct|state=SC|SC|34|dir1=east|city1=Ridgeway}}
|notes=East end of SC&nbsp;34 overlap; to South Carolina Railroad Museum}}
{{SCint
|mile=152.7
|road={{jct|state=SC|US-Bus|321|SC|213|dab1=Winnsboro|dir1=north|dir2=west|name1=Columbia Road|name2=Monjicono Road|city1=Monticello}}}}
{{SCint
|location=Winnsboro
|lspan=2
|type=concur
|mile=156.1
|road={{jct|state=SC|SC|34|SC|200|dir1=west|dir2=east|name1=Newberry Road|city1=Newberry|city2=Great Falls}}
|notes=West end of SC&nbsp;34 overlap}}
{{SCint
|mile=156.9
|road={{jct|state=SC|US-Bus|321|dab1=Winnsboro|dir1=south|name1=Congress Street}}}}
{{SCint
|county=Chester
|cspan=7
|location=Chester
|lspan=6
|type=concur
|mile=178.8
|road={{jct|state=SC|SC|97|dir1=south|name1=Great Falls Road|city1=Great Falls|city2=Camden}}
|notes=South end of SC&nbsp;97 overlap}}
{{SCint
|type=concur
|mile=179.4
|road={{jct|state=SC|US-Bus|321|dab1=Chester|dir1=north|name1=Columbia Road}}<br />{{jct|state=SC|SC|9|SC|72|SC|97|SC|121|dir1=south|dir2=east|dir3=north|dir4=north|name4=J.A. Cochran Bypass}}
|notes=South end of SC&nbsp;9, east end of SC&nbsp;72, and north end of SC&nbsp;97/SC&nbsp;121 overlap}}
{{SCint
|type=concur
|mile=181.2
|road={{jct|state=SC|SC|72|SC|121|dir1=west|dir2=south|name2=West End Road|city1=Carlisle|city2=Whitmire}}
|notes=West end of SC&nbsp;72 and south end of SC&nbsp;121 overlap}}
{{SCint
|mile=182.0
|road={{jct|state=SC|SC-Bus|9|dab1=Chester|dir1=south|name1=Pinckney Street}}}}
{{SCint
|type=concur
|mile=182.3
|road={{jct|state=SC|SC|9|dir1=north|name1=Pinckney Street|city1=Lockhart}}
|notes=North end of SC&nbsp;9 overlap}}
{{SCint
|mile=184.2
|road={{jct|state=SC|US-Bus|321|SC|97|dab1=Chester|dir1=south|name2=Center Road|city1=Hickory Grove}}}}
{{SCint
|location=Lowrys
|mile=189.7
|road={{jct|state=SC|SC|909|dir1=south|name1=Old York Road|city1=Lewis}}}}
{{SCint
|county=York
|cspan=9
|location=McConnells
|lspan=2
|type=concur
|mile=194.2
|road={{jct|state=SC|SC|322|dir1=west|name1=Church Street}}
|notes=West end of SC&nbsp;322 overlap}}
{{SCint
|type=concur
|mile=194.3
|road={{jct|state=SC|SC|322|dir1=east|name1=McConnells Highway|city1=Rock Hill}}
|notes=West end of SC&nbsp;322 overlap; to [[Historic Brattonsville]]}}
{{SCint
|location=York
|lspan=5
|mile=203.3
|road={{jct|state=SC|US-Bus|321|dab1=York|name1=Congress Street}}}}
{{SCint
|mile=203.7
|road={{jct|state=SC|SC|49|name1=Sharon Road|city1=Sharon|city2=Union}}}}
{{SCint
|type=concur
|mile=204.5
|road={{jct|state=SC|SC-Bus|5|SC-Bus|161|dab1=York|dab2=York|dir2=south|name2=Liberty Street|city1=Blacksburg}}
|notes=South end of SC&nbsp;161 Bus overlap}}
{{SCint
|mile=205.7
|road={{jct|state=SC|US-Bus|321|dab1=York|name1=Kings Mountain Street}}}}
{{SCint
|type=concur
|mile=205.9
|road={{jct|state=SC|SC|5|SC|161|dir2=south|name2=Alexander Love Highway|city1=Blacksburg}}
|notes=South end of SC&nbsp;161 and north end of SC&nbsp;161 Bus overlap}}
{{SCint
|location=Filbert
|type=concur
|mile=207.5
|road={{jct|state=SC|SC|161|dir1=north|city1=Bethany}}
|notes=North end of SC&nbsp;161 overlap}}
{{SCint
|location=Clover
|mile=213.4
|road={{jct|state=SC|SC|55|name1=Kings Mountain/Bethel Streets|city1=Lake Wylie|city2=Blacksburg}}}}
{{jctplace|river_wide=yes|river=&nbsp;|mile=217.2|mile2=0.0|line=yes|place=South Carolina–North Carolina state line}}
{{NCint
|sspan=33
|county=Gaston
|cspan=7
|location=Gastonia
|lspan=4
|mile=7.3
|road=Garrison Boulevard}}
{{NCint
|mile=7.9
|road={{jct|state=NC|US|29|US|74|name2=Franklin Boulevard}}}}
{{NCint
|mile=8.1
|road={{jct|state=NC|NC|7|dir1=east|name1=Long Avenue}}}}
{{NCint
|mile=9.4
|road={{jct|state=NC|I|85|city1=Charlotte|location2=[[Spartanburg, South Carolina|Spartanburg]]}}}}
{{NCint
|location=Dallas
|lspan=2
|mile=9.4
|road=Grier Beem Boulevard &ndash; [[Gaston College]]|notes=Signed exit 11}}
{{NCint
|mile=11.7
|road={{jct|state=NC|US-Bus|321|NC|275|NC|279|dab1=Newton|dir1=north|name3=Dallas-Cherryville Highway|city1=Cherryville}}|notes=Signed exits 12A-B Northbound and exit 12 Southbound}}
{{NCint
|location=none
|mile=16.1
|road=Hardin Road|notes=Signed exit 17}}
{{NCint
|county=Lincoln
|cspan=3
|location=none
|mile=18.8
|road={{jct|state=NC|US-Bus|321|dab1=Newton|name1=Gastonia Highway|city1=High Shoals|city2=Lincolnton}}
|notes=Signed exit 20}}
{{NCint
|location=Lincolnton
|mile=23.6
|road={{jct|state=NC|NC|27|NC|150|name2=Main Street|city1=Lincolnton}}
|notes=Signed exit 24}}
{{NCint
|location=none
|mile=27.0
|road={{jct|state=NC|US-Bus|321|dab1=Newton|name1=Maiden Highway|city1=Maiden}}
|notes=Signed exit 28}}
{{NCint
|county=Catawba
|cspan=7
|location=Maiden
|mile=32.3
|road=Startown Road
|notes=Signed exit 33}}
{{NCint
|location=none
|mile=36.2
|road={{jct|state=NC|NC|10|city1=Newton}}
|notes=Signed exit 37}}
{{NCint
|location=none
|mile=40.1
|road=River Road
|notes=Signed exit 41}}
{{NCint
|location=Mountain View
|mile=41.4
|road={{jct|state=NC|NC|127|name1=Brookford Boulevard}}
|notes=Signed exit 42}}
{{NCint
|location=Hickory
|lspan=3
|mile=42.3
|road={{jct|state=NC|I|40|city1=Statesville|city2=Asheville}}
|notes=Signed exits 43A (east) and 43B (west)}}
{{NCint
|mile=43.3
|road={{jct|state=NC|US|70|US-Bus|321|NC|127|dab2=Newton|dir2=south|to3=to|name3=Conover Boulevard|city1=Hickory}}
|notes=Signed exit 44}}
{{NCint
|mile=45.3
|road=Clement Boulevard &ndash; [[Hickory Regional Airport]]}}
{{jctco|state=NC|county=Burke}}
{{NCint
|county=Caldwell
|cspan=7
|location=Northlakes
|mile=47.9
|road={{jct|state=NC|US|321A|dir1=north|city1=Granite Falls}}}}
{{NCint
|location=Granite Falls
|mile=50.1
|road=Falls Avenue &ndash; [[Granite Falls, North Carolina|Granite Falls]]}}
{{NCint
|location=Lenoir
|lspan=4
|mile=56.8
|road=Southwest Boulevard &ndash; [[Morganton, North Carolina|Morganton]]}}
{{NCint
|mile=59.1
|road={{jct|state=NC|US|321A|dir1=south|city1=Hudson}}}}
{{NCint
|type=concur
|mile=60.1
|road={{jct|state=NC|US|64|NC|18|NC|90|dir3=east|city1=Lenoir|city2=Wilkesboro}}
|notes=East end of NC&nbsp;90 overlap}}
{{NCint
|type=concur
|mile=62.3
|road={{jct|state=NC|NC|90|dir1=west|name1=Main Street|city1=Lenoir|city2=Collettsville}}
|notes=West end of NC&nbsp;90 overlap}}
{{NCint
|location=none
|mile=65.9
|road={{jct|state=NC|NC|268|dir1=east|location1=[[Fort Defiance (Lenoir, North Carolina)|Fort Defiance]]}}}}
{{NCint
|county=Watauga
|cspan=7
|location=Blowing Rock
|lspan=3
|mile=79.4
|road={{jct|state=NC|US-Bus|321|dab1=Blowing Rock|dir1=north|name1=Main Street}}}}
{{NCint
|type=concur
|mile=80.6
|road={{jct|state=NC|US|221|US-Bus|321|dab2=Blowing Rock|dir1=south|dir2=south}}
|notes=South end of US&nbsp;221 overlap}}
{{NCint
|mile=81.4
|road={{jct|state=NC|BRP}}
|notes=To [[Moses H. Cone Memorial Park]] and [[Julian Price Memorial Park]]}}
{{NCint
|location=Boone
|lspan=2
|type=concur
|mile=87.0
|road={{jct|state=NC|US|221|NC|105|dir1=north|city1=Linville|city2=Banner Elk|city3=Newland}}
|notes=North end of US&nbsp;221 overlap}}
{{NCint
|type=concur
|mile=87.9
|road={{jct|state=NC|US|421|NC|194|dir1=south|dir2=north|name2=King Street}}
|notes=South end of US&nbsp;421 and north end of NC&nbsp;194 overlap}}
{{NCint
|location=Vilas
|type=concur
|mile=93.6
|road={{jct|state=NC|NC|194|dir1=south|city1=Valle Crucis}}
|notes=South end of NC&nbsp;194 overlap}}
{{NCint
|location=Sugar Grove
|type=concur
|mile=94.3
|road={{jct|state=NC|US|421|dir1=north|location1=[[Mountain City, Tennessee|Mountain City]]}}
|notes=North end of US&nbsp;421 overlap}}
{{jctco|state=NC|county=Avery}}
{{jctplace|river_wide=yes|river=&nbsp;|mile=105.5|mile2=0.0|line=yes|place=North Carolina–Tennessee state line}}
{{TNint
|sspan=58
|county=Carter
|cspan=7
|location=none
|type=concur
|mile=12.5
|road={{jct|state=TN|SR|67|dir1=east|city1=Mountain City}}
|notes=East end of SR&nbsp;67 and west end of [[Tennessee State Route 159|SR&nbsp;159]] (hidden) overlap}}
{{TNint
|location=Hampton
|type=concur
|mile=12.5
|road={{jct|state=TN|US|19E|dir1=south|name1=[[Tennessee State Route 37|SR&nbsp;37]]|city1=Roan Mountain}}
|notes=South end of US&nbsp;19E overlap}}
{{TNint
|location=Elizabethton
|lspan=5
|type=concur
|mile=27.2
|mspan=2
|road={{jct|state=TN|US|19E|Sec|91|dir3=north|name2=[[Tennessee State Route 37|SR&nbsp;37]]|city1=Bluff City}}
|notes=North end of US&nbsp;19E and SR&nbsp;91 overlap}}
{{jctplace
|mile=none
|type=trans
|place=Route transition from northbound to southbound}}
{{TNint
|mile=28.0
|road={{jct|state=TN|Sec|400|dir1=south|city1=Watauga}}}}
{{TNint
|type=concur
|mile=31.3
|road={{jct|state=TN|Sec|91|Sec|362|dir2=south}}
|notes=South end of SR&nbsp;91 overlap}}
{{TNint
|mile=31.9
|road={{jct|state=TN|Sec|359|dir1=south|location1=[[Milligan College]]}}}}
{{TNint
|county=Washington
|cspan=8
|location=Johnson City
|lspan=4
|mile=35.3
|road=Legion Street / Milligan Highway
|notes=Interchange}}
{{TNint
|mile=35.8
|road={{jct|state=TN|I|26|US|19W|US|23|city1=Erwin|city2=Kingsport}}
|notes=Intrechange; exit 24 (I-26)}}
{{TNint
|type=concur
|mile=36.7
|road={{jct|state=TN|Sec|67|SR|381|dir1=west|name2=Cherokee Road}}
|notes=West end of SR&nbsp;67 and south end of SR&nbsp;381 overlap}}
{{TNint
|type=concur
|mile=39.5
|road={{jct|state=TN|US|11E|SR|381|dir2=north|name2=[[Tennessee State Route 34|SR&nbsp;34]] / State of Franklin Road}}
|notes=North end of US&nbsp;11E and SR&nbsp;381 overlap}}
{{TNint
|location=Jonesborough
|lspan=3
|mile=44.3
|road={{jct|state=TN|Sec|354|name1=Boones Creek Road|road|Boone Street|city1=Boones Creek|location2=Business District}}}}
{{TNint
|mile=
|road={{jct|state=TN|TN|81|city1=Kingsport|city2=Erwin|road|Washington Drive|to1=to|location3=Business District}}
|notes=}}
{{TNint
|mile=
|road={{jct|state=TN|TN|81|road|Persimmon Ridge Road|to1=to|city1=Lamar|city2=Erwin}}
|notes=}}
{{TNint
|location=Limestone
|mile=54.4
|road={{jct|state=TN|Sec|75|dir1=north|name1=Opie Arnold Road}}}}
{{TNint
|county=Greene
|cspan=12
|location=none
|mile=58.0
|road={{jct|state=TN|Sec|351|name1=Chuckey Pike|city1=Chuckey|city2=Rheatown}}}}
{{TNint
|location=Tusculum
|type=concur
|mile=62.6
|road={{jct|state=TN|SR|107|dir1=east|name1=Tusculum Bypass|city1=Erwin|location2=[[Tusculum College]]}}
|notes=East end of SR&nbsp;107 (hidden) overlap}}
{{TNint
|location=Greeneville
|lspan=10
|road=Erwin Highway – [[Tusculum, Tennessee|Tusculum]], [[Tusculum College]]
|notes=Former SR&nbsp;107}}
{{TNint
|type=concur
|mile=65.2
|road={{jct|state=TN|US-Bus|11E|dab1=Greeneville|dir1=south|name1=[[Tennessee State Route 107|SR&nbsp;107]] / Tusculum Boulevard}}
|notes=West end of SR&nbsp;107 (hidden) overlap}}
{{TNint
|mile=66.0
|road=Snapps Ferry Road
|notes=Interchange}}
{{TNint
|type=concur
|mile=67.1
|road={{jct|state=TN|US|11E|SR|93|dir1=south|dir2=north|name1=[[Tennessee State Route 34|SR&nbsp;34]]|name2=Kingsport Highway|city1=Kingsport|city2=Morristown}}
|notes=South end of US&nbsp;11E overlap; southern terminus of SR&nbsp;93}}
{{TNint
|mile=67.3
|road={{jct|state=TN|Sec|172|dir1=north|name1=Baileyton Road|extra=Airport|city1=Baileyton|location2=[[Greeneville-Greene County Municipal Airport|Airport]]}}
|notes=Southern terminus of SR&nbsp;172}}
{{TNint
|type=concur
|mile=68.0
|road={{jct|state=TN|US-Bus|11E|dab1=Greeneville|dir1=north|name1=[[Tennessee State Route 107|SR&nbsp;107]] / Tusculum Boulevard}}
|notes=North end of US&nbsp;11E Bus. overlap}}
{{TNint
|type=concur
|mile=68.4
|road={{jct|state=TN|US-Bus|11E|Sec|350|dab1=Greeneville|dir1=south|dir2=north|name1=[[Tennessee State Route 350|SR&nbsp;350]] / West Summer Street}}
|notes=South end of US&nbsp;11E Bus. overlap}}
{{TNint
|type=concur
|mile=68.5
|road={{jct|state=TN|Sec|350|dir1=south|name1=McKee Street}}
|notes=South end of SR&nbsp;350 (hidden) overlap}}
{{TNint
|type=concur
|mile=69.5
|road={{jct|state=TN|SR|70|Sec|107|dir2=west|name2=Asheville Highway}}
|notes=West end of SR&nbsp;107 (hidden) overlap}}
{{TNint
|mile=71.3
|road={{jct|state=TN|Sec|349|dir1=west|name1=Warrensburg Road}}
|notes=Eastern terminus of SR 349}}
{{TNint
|county=Cocke
|cspan=9
|location=Parrottsville
|mile=87.3
|road={{jct|state=TN|Sec|340|city1=Parrottsville|city2=Del Rio}}}}
{{TNint
|location=none
|mile=91.6
|road={{jct|state=TN|Sec|160|dir1=north|city1=Bybee}}
|notes=Southern terminus of SR 160}}
{{TNint
|location=Newport
|lspan=3
|type=concur
|mile=93.7
|road={{jct|state=TN|US|25|US|70|dir1=south|name2=[[Tennessee State Route 9|SR&nbsp;9]] / Broadway Street}}
|notes=South end of US&nbsp;25 and east end of US&nbsp;70 overlap}}
{{TNint
|type=concur
|mile=94.0
|road={{jct|state=TN|US|25|US|70|TN|32|name1=[[Tennessee State Route 9|SR&nbsp;9]]|name2=[[Tennessee State Route 35|SR&nbsp;35]]|dir1=north|dir2=west|dir3=north|name3=Broadway Street}}
|notes=North end of US&nbsp;25 / SR&nbsp;32 and west end of US&nbsp;70 overlap}}
{{TNint
|mile=95.5
|road={{jct|state=TN|I|40|city1=Knoxville|location2=[[Asheville, North Carolina|Asheville]]}}
|notes=I-40 exit 435}}
{{TNint
|location=none
|type=concur
|mile=101.1
|road={{jct|state=TN|Sec|73|dir1=north|name1=Wilton Springs Road}}
|notes=North end of SR&nbsp;73 (hidden) overlap}}
{{TNint
|location=Cosby
|lspan=3
|mile=106.0
|road={{jct|state=TN|Sec|339|dir1=west|name1=Jones Cove Road|city1=Cherokee Hills}}
|notes=Eastern terminus of SR 339}}
{{TNint
|mile=106.2
|road={{jct|state=TN|road|[[Foothills Parkway]]|to2=to|I|40}}
|notes=Western terminus of section 8A of the Foothills Parkway}}
{{TNint
|type=concur
|mile=108.0
|road={{jct|state=TN|Sec|32|dir1=south}}
|notes=South end of SR&nbsp;32 overlap}}
{{TNint
|county=Sevier
|cspan=7
|location=Pittman Center
|mile=119.9
|road={{jct|state=TN|Sec|416|dir1=north|name1=Pittman Center Road}}
|notes=Southern terminus of SR 416}}
{{TNint
|location1=Gatlinburg
|location2=Pittman Center
|mile=120.8
|road={{jct|state=TN|Sec|454|dir1=north|name1=Buckhorn Road}}
|notes=Southern terminus of SR 454}}
{{TNint
|location=Gatlinburg
|lspan=2
|type=concur
|mile=126.1
|road={{jct|state=TN|US|441|Sec-Scenic|73|dir1=south|dir2=west|name2=[[Great Smoky Mountains Parkway|Parkway]]/[[Tennessee State Route 71|SR&nbsp;71]]|location1=[[Great Smoky Mountains National Park]]}}
|notes=South end of US&nbsp;441 overlap; eastern terminus of SR 73 Scenic}}
{{TNint
|type=incomplete
|mile=127.2
|road=[[Gatlinburg Bypass|Gatlinburg Parkway Bypass]] &ndash; [[Great Smoky Mountains National Park]]
|notes=No access from northbound US&nbsp;441/US&nbsp;321}}
{{TNint
|location=Pigeon Forge
|lspan=2
|mile=
|road={{jct|state=TN|TN|449|name1=Dollywood Lane|dir1=North|location1=[[Dollywood]]}}
|notes=Southern terminus of SR&nbsp;449}}
{{TNint
|type=concur
|mile=134.5
|road={{jct|state=TN|US|441|name1=[[Great Smoky Mountains Parkway|Parkway]]/[[Tennessee State Route 71|SR&nbsp;71]]|dir1=north|city1=Sevierville}}
|notes=North end of US&nbsp;441 overlap}}
{{TNint
|location=Wears Valley
|mile=142.9
|road=[[Foothills Parkway]]
|notes=Interchange; eastern terminus of western section of Foothills Parkway}}
{{TNint
|county=Blount
|cspan=9
|location=Townsend
|mile=149.4
|road={{jct|state=TN|Sec-Scenic|73|dir1=east|name1=East Lamar Alexander Parkway/SR 337|location1=[[Great Smoky Mountains National Park]]}}
|notes=Western terminus of SR 73 Scenic}}
{{TNint
|location=Walland
|mile=156.8
|road=[[Foothills Parkway]] – [[Top of The World, Tennessee|Top of The World]], [[Chilhowee Dam|Chilhowee Lake]], [[Great Smoky Mountains National Park]] Look Rock area
|notes=Interchange}}
{{TNint
|location=Maryville
|lspan=6
|mile=166.7
|road={{jct|state=TN|Sec|447|US|411|dir1=north|to2=to|dir2=north|name1=Washington Street}}
|notes=Southern terminus of SR 447}}
{{TNint
|mile=167.4
|road={{jct|state=TN|Sec|336|name1=Montvale Road|dir1=south}}
|notes=Northern terminus of SR 336}}
{{TNint
|mile=167.6
|road={{jct|state=TN|US|411|name1=Broadway Avenue/[[Tennessee State Route 33|SR 33]]|city1=Rockford|city2=Madisonville}}}}
{{TNint
|mile=168.7
|road={{jct|state=TN|US|129|name1=[[Tennessee State Route 115|SR 115]]|city1=Alcoa|city2=Knoxville}}}}
{{TNint
|type=concur
|mile=171.0
|road={{jct|state=TN|Sec|335|dir1=north|name1=Old Glory Road}}
|notes=North end of SR&nbsp;335 overlap}}
{{TNint
|type=concur
|mile=171.6
|road={{jct|state=TN|Sec|335|dir1=south|name1=William Blount Drive}}
|notes=South end of SR&nbsp;335 overlap}}
{{TNint
|location=Friendsville
|mile=176.1
|road={{jct|state=TN|Sec|333|dir1=north|name1=Main Avenue|city1=Friendsville}}
|notes=Southern terminus of SR 333}}
{{TNint
|county=Loudon
|cspan=6
|location=none
|type=concur
|mile=181.4
|road={{jct|state=TN|Sec|95|dir1=south|name1=Lenoir City Road|city1=Greenback}}
|notes=South end of SR&nbsp;95 (hidden) overlap}}
{{TNint
|location=none
|mile=185.0
|road={{jct|state=TN|Sec|444|dir1=west|name1=Tellico Parkway|city1=Tellico Village}}
|notes=Eastern terminus of SR 444}}
{{TNint
|location=Lenoir City
|lspan=4
|mile=186.8
|road={{jct|state=TN|US|11|name1=Broadway Street/[[Tennessee State Route 2|SR 2]]|city1=Knoxville|city2=Loudon|city3=Farragut}}}}
{{TNint
|mile=189.5
|road={{jct|state=TN|I|75|city1=Knoxville|city2=Chattanooga}}
|notes=I-75 exit 81}}
{{TNint
|mile=190.3
|road={{jct|state=TN|US|70|name1=Kingston Pike/[[Tennessee State Route 1|SR 1]]|city1=Knoxville|city2=Kingston}}}}
{{TNint
|type=concur
|mile=194.2
|road={{jct|state=TN|I|40|SR|95|name2=White Wing Road|dir2=north|city1=Knoxville|city2=Nashville|city3=Oak Ridge}}
|notes=West end of SR&nbsp;73 (hidden) and north end of SR&nbsp;95 (hidden) overlap; I-40 exit 364}}
{{Jctbtm|col=7|keys=concur,trans,unbuilt}}
{{Clear}}

==Special routes==
<!--{{Split section|date=May 2016|Special routes of U.S. Route 321}}-->

===Winnsboro business loop===
{{infobox road small
|state=SC
|type=US-Bus
|route=321

|location=[[Winnsboro, South Carolina]]
|formed=1952{{citation needed|date=December 2020}}
|length_mi=4.350
|length_round=3
|length_ref=<ref>{{cite web |url=https://ris.scdot.org/LogMileReport.aspx?county=20&type=2&number=321&auxiliary=7&map=y |title=Highway Logmile Report |publisher=[[South Carolina Department of Transportation]] |access-date=December 11, 2020 }}</ref>
}}
'''U.S. Route&nbsp;321 Business''' ('''US&nbsp;321 Bus.''') is a {{convert|4.350|mi|km|adj=on}} [[business route]] of US&nbsp;321 that exists in [[Winnsboro Mills, South Carolina|Winnsboro Mills]] and [[Winnsboro, South Carolina|Winnsboro]], via Columbia Road and Congress Street.<ref>{{google maps |url=https://maps.google.com/maps?saddr=US-321BUS+S&daddr=34.379378,-81.0860539+to:US-321BUS+N&hl=en&ll=34.376241,-81.077299&spn=0.061702,0.111494&sll=34.397137,-81.080475&sspn=0.061686,0.111494&geocode=FcsXDAIdcrIq-w%3BFXKWDAIdm7kq-ym_-hyBSBdWiDG19RxNCfAUhQ%3BFd_2DAIdkXwq-w&mra=dme&mrsp=2&sz=14&via=1&t=p&z=14 |title=Overview map of US&nbsp;321 Bus. (Winnsboro, South Carolina) |access-date=December 1, 2013 }}</ref> It was established around 1951 or 1952, when mainline US&nbsp;321 was rerouted west, bypassing Winnsboro.{{citation needed|date=December 2020}}
{{Clear}}

===Chester business loop===
{{infobox road small
|state=SC
|type=US-Bus
|route=321

|location=[[Chester, South Carolina]]
|formed=1964{{citation needed|date=December 2020}}
|length_mi=3.670
|length_round=3
|length_ref=<ref>{{cite web |url=https://ris.scdot.org/LogMileReport.aspx?county=12&type=2&number=321&auxiliary=7&map=y |title=Highway Logmile Report |publisher=South Carolina Department of Transportation |access-date=December 11, 2020 }}</ref>
}}
'''U.S. Route&nbsp;321 Business''' ('''US&nbsp;321 Bus.''') is a {{convert|3.670|mi|km|adj=on}} [[business route]] of US&nbsp;321 in the city of [[Chester, South Carolina|Chester]]. It traverses downtown Chester, via Columbia Street and Center Road.<ref>{{google maps |url=https://maps.google.com/maps?saddr=SC-97+Business+N%2FUS-321BUS+S%2FColumbia+Rd&daddr=SC-97+N%2FSC-97+Business+N%2FUS-321BUS+S%2FCenter+Rd&hl=en&ll=34.709797,-81.198063&spn=0.061455,0.111494&sll=34.732064,-81.237003&sspn=0.00384,0.006968&geocode=FVBYEQIdugAp-w%3BFeT5EQIdNWIo-w&mra=me&mrsp=1,0&sz=18&t=p&z=14 |title=Overview map of US&nbsp;321 Bus. (Chester, South Carolina) |link=no |access-date=December 1, 2013 }}</ref> It was established between 1962 and 1964, when mainline US&nbsp;321 was rerouted west, bypassing Chester.{{citation needed|date=December 2020}}
{{Clear}}

===York business loop===
{{infobox road small
|state=SC
|type=US-Bus
|route=321

|location=[[York, South Carolina]]
|formed=1958{{citation needed|date=December 2020}}
|length_mi=2.500
|length_round=3
|length_ref=<ref>{{cite web |url=https://ris.scdot.org/LogMileReport.aspx?county=46&type=2&number=321&auxiliary=7&map=y |title=Highway Logmile Report |publisher=South Carolina Department of Transportation |access-date=December 11, 2020 }}</ref>
}}
'''U.S. Route&nbsp;321 Business''' ('''US&nbsp;321 Bus.''') is a {{convert|2.500|mi|km|adj=on}} [[business route]] of US&nbsp;321 in the city of [[York, South Carolina|York]], utilizing Congress Street and Kings Mountain Street.<ref>{{google maps |url=https://maps.google.com/maps?saddr=US-321+Bypass+N&daddr=34.9995659,-81.2391874+to:Kings+Mountain+St&hl=en&ll=34.997308,-81.226988&spn=0.061241,0.111494&sll=35.000683,-81.234241&sspn=0.030619,0.055747&geocode=FUvKFQIdhUUo-w%3BFQ0NFgIdbWMo-ylD6_ig7_NWiDH5SvXdKska-g%3BFahHFgIdsUIo-w&mra=dpe&mrsp=1&sz=15&via=1&t=p&z=14 |title=Overview map of US&nbsp;321 Bus. (York, South Carolina) |link=no |access-date=December 1, 2013 }}</ref> It was established around 1957–1958, when mainline US&nbsp;321 was rerouted west, bypassing York.{{citation needed|date=December 2020}}
{{Clear}}

===Dallas&ndash;Hickory business loop===
{{infobox road small
|state=NC
|type=US-Bus
|route=321

|location=[[Dallas, North Carolina|Dallas]]&ndash;[[Hickory, North Carolina|Hickory, NC]]
|formed=1999
|length_mi=37.2
|length_round=1
|length_ref=<ref>{{google maps|url=https://maps.google.com/maps?saddr=W+Trade+St&daddr=35.383145,-81.2097839+to:35.4496258,-81.2407278+to:35.4859072,-81.2435056+to:35.617174,-81.216005+to:35.695288,-81.237315+to:US-321Bus+N%2FUS-70+W&hl=en&ll=35.536138,-81.100388&spn=0.486675,0.891953&sll=35.442351,-81.223812&sspn=0.121811,0.222988&geocode=FYfhGgIdty4p-w%3BFWnnGwIdSdYo-ylJT_NmU8ZWiDEtaJtRFQloeA%3BFRnrHAIdaV0o-ym_pnoBxshWiDHmUbtIjAvj0A%3BFdN4HQIdj1Io-yl7FMwAN8lWiDGKvxo4DxyssQ%3BFZZ5HwId-70o-ymPDI9k5zRRiDGde-B7UMxTbg%3BFbiqIAIdvWoo-ylRtOKRvDZRiDHLYCSsUFMMGQ%3BFSoUIQIdCJom-w&mra=dpe&mrsp=2&sz=13&via=1,2,3,4,5&t=p&z=11|title=US 321 Business - Dallas-Hickory, North Carolina|access-date=December 1, 2013}}</ref>
}}
'''U.S. Route 321 Business''' ('''US&nbsp;321 Bus''') was established in June 1999, as a renumbering all of NC&nbsp;155 and part of mainline US&nbsp;321 in [[Catawba County, North Carolina|Catawba County]].  Traversing {{convert|37.2|mi|km}} through [[Gaston County, North Carolina|Gaston]], [[Lincoln County, North Carolina|Lincoln]] and Catawba counties, it connects the cities and towns of Dallas, [[High Shoals, North Carolina|High Shoals]], [[Lincolnton, North Carolina|Lincolnton]], [[Maiden, North Carolina|Maiden]], [[Newton, North Carolina|Newton]], [[Conover, North Carolina|Conover]] and Hickory.  The highway follows the original US&nbsp;321 routing through that existed prior to 1994.<ref name="1999 Route Change"/>
{{Clear}}

===Lincolnton alternate route===
{{infobox road small
|state=NC
|type=US
|route=321A
|location=[[Lincolnton, North Carolina]]
|formed=1956
|deleted=1960
|length_mi=3.4
|length_round=1
|length_ref=<ref>{{google maps |url=https://maps.google.com/maps?saddr=US-321Bus+N%2FS+Aspen+St&daddr=N+Aspen+St&hl=en&ll=35.472973,-81.224155&spn=0.060883,0.111494&sll=35.493198,-81.247866&sspn=0.007346,0.004774&geocode=FUn3HAIdFlIo-w%3BFX-ZHQId9kUo-w&mra=me&mrsp=1,0&sz=17&t=p&z=14|title=US 321A - Lincolnton, North Carolina|access-date=December 1, 2013}}</ref>
}}
'''U.S. Route 321 Alternate''' ('''US&nbsp;321A''') was established 1956 when mainline US&nbsp;321 was placed on new bypass east of downtown Lincolnton.  It traversed along Aspen Street and around the Lincoln County Civil Court on Court Square Drive.  In 1960 it was decommissioned, with Aspen Street becoming secondary roads.
{{Clear}}

===Granite Falls&ndash;Lenoir alternate route===
{{infobox road small
|state=NC
|type=US
|route=321A
|location=[[Granite Falls, North Carolina|Granite Falls]]&ndash;[[Lenoir, North Carolina|Lenoir, NC]]
|formed=1948
|length_mi=11.8
|length_round=1
|length_ref=<ref>{{google maps |url=https://maps.google.com/maps?saddr=US-321Alt+N%2FS+Main+St&daddr=35.8467155,-81.4944551+to:McLean+Dr+SW&hl=en&ll=35.837577,-81.423454&spn=0.24242,0.445976&sll=35.856083,-81.490488&sspn=0.060591,0.111494&geocode=FSftIQIdXAAm-w%3BFTv6IgIdSX4k-ylld6O3bCdRiDGIxg-L6FDnYw%3BFZ_FIwIdxBAk-w&mra=dpe&mrsp=1&sz=14&via=1&t=p&z=12|title=US 321A - Granite Falls-Lenoir, North Carolina|access-date=December 1, 2013}}</ref>
}}
'''U.S. Route 321 Alternate''' ('''US&nbsp;321A''') was established 1948 as a number swap with US&nbsp;321 through downtown Lenoir.  In 1957, US&nbsp;321A was extended south, replacing mainline US&nbsp;321 through [[Granite Falls, North Carolina|Granite Falls]] and [[Hudson, North Carolina|Hudson]], ending at its current southern terminus north of the [[Catawba River]].  In June 1964, US&nbsp;321A was placed on one-way splits through downtown Lenoir; northbound continued along Mulberry Street and West Avenue, southbound rerouted along Main Street and College Avenue.  In September 2006, US&nbsp;321A was rerouted to its current northern terminus, just south of downtown Lenoir, via McLean Drive.  Its old alignment through downtown Lenoir was carried on by [[North Carolina Highway 90|NC&nbsp;90]] until 2012, when it too was rerouted; the old alignment is now under city control.<ref>{{cite web |publisher= North Carolina Department of Transportation |url= https://connect.ncdot.gov/resources/safety/Route%20Changes/1964_06_04.pdf |title= US 321A Route Change (1964-06-04) |date= June 4, 1964 |access-date= December 1, 2013}}</ref><ref>{{cite web |publisher= North Carolina Department of Transportation |url= https://connect.ncdot.gov/resources/safety/Route%20Changes/2006_09_07a.pdf |title= US 321A Route Change (2006-09-07) |date= September 7, 2006 |access-date= December 1, 2013}}</ref><ref>{{cite web |publisher= North Carolina Department of Transportation |url= https://connect.ncdot.gov/resources/safety/Route%20Changes/2012_12_11.pdf |title= Correction to Caldwell County Route |date= December 11, 2012 |access-date= December 1, 2013}}</ref>

Traversing through Granite Falls, [[Sawmills, North Carolina|Sawmills]], Hudson and [[Lenoir, North Carolina|Lenoir]] US&nbsp;321A has not changed much over the years. Predominantly a two-lane highway, it parallels a short line railroad and connects to several factories and downtowns.
{{Clear}}

===Lenoir alternate route===
{{infobox road small
|state=NC
|type=US
|route=321A
|location=[[Lenoir, North Carolina]]
|formed=1941
|deleted=1948
|length_mi=5.9
|length_round=1
|length_ref=<ref>{{google maps |url=https://maps.google.com/maps?saddr=US-321+S%2FBlowing+Rock+Blvd&daddr=US-321Alt&hl=en&ll=35.919918,-81.518726&spn=0.121084,0.222988&sll=35.892892,-81.522267&sspn=0.015141,0.027874&geocode=FYqxJAIdeWwj-w%3BFc2lIwIdwAck-w&mra=dme&mrsp=1&sz=16&t=p&z=13|title=US 321A - Lenoir, North Carolina|access-date=December 1, 2013}}</ref>
}}
'''U.S. Route 321 Alternate''' ('''US&nbsp;321A''') was established 1941 as a new alternate route bypassing Lenoir.  In 1948, it was replaced by mainline US&nbsp;321.
{{Clear}}
[[File:US 221 and US 321 Business in Blowing Rock.JPG|thumb|left|[[U.S. Route 221 in North Carolina|US&nbsp;221]]/US&nbsp;321 Bus. in [[Blowing Rock, North Carolina|Blowing Rock]]]]

===Blowing Rock business loop===
{{infobox road small
|state=NC
|type=US-Bus
|route=321

|location=[[Blowing Rock, North Carolina]]
|formed=1960
|length_mi=2.0
|length_round=1
|length_ref=<ref>{{google maps |url=https://maps.google.com/maps?saddr=Main+St&daddr=Main+St&hl=en&ll=36.129903,-81.667857&spn=0.030191,0.055747&sll=36.137095,-81.670464&sspn=0.007547,0.013937&geocode=FaorJwIdW8sh-w%3BFf5zJwIdJtIh-w&mra=dme&mrsp=1&sz=17&t=p&z=15|title=US 321 Business - Blowing Rock, North Carolina|access-date=December 1, 2013}}</ref>
}}
'''U.S. Route 321 Business''' ('''US&nbsp;321 Bus''') was established 1960 as an upgrade to secondary roads through downtown Blowing Rock; which were originally part of mainline US&nbsp;321 until about 1954, when it was moved onto a new bypass east.  The highway traverses along Main Street and shares a concurrency with [[U.S. Route 221 in North Carolina|US&nbsp;221]] for {{convert|0.8|mi|km}} on its northern section.
{{Clear}}
[[File:NC 105 with Truck Signs.jpg|thumb|left|[[U.S. Route 221 Truck (Linville-Boone, North Carolina)|US&nbsp;221 Truck]]/US&nbsp;321 Truck/[[U.S. Route 421 Truck (Boone, North Carolina)|US&nbsp;421 Truck]]/[[North Carolina Highway 105|NC&nbsp;105]] traveling concurrent through the [[Boone, North Carolina|Boone]] area]]

===Boone truck route===
{{infobox road small
|state=NC
|type=US-Truck
|route=321

|location=[[Boone, North Carolina]]
|formed=
|length_mi=4.0
|length_round=1
|length_ref=<ref>{{google maps |url=https://maps.google.com/maps?saddr=US-221+N%2FUS-321+N&daddr=NC+Highway+105+Bypass&hl=en&ll=36.213394,-81.692362&spn=0.060317,0.111494&sll=36.229681,-81.72071&sspn=0.001885,0.003484&geocode=FSN0KAIdNNIh-w%3BFQXVKAIdCAsh-w&mra=me&mrsp=1,0&sz=19&t=p&z=14|title=US 321 Truck - Boone, North Carolina|access-date=December 4, 2013}}</ref>
}}

'''U.S. Route 321 Truck''' ('''US&nbsp;321 Truck''') redirects truckers traveling through the area to go south and around downtown Boone, via [[North Carolina Highway 105|NC&nbsp;105]] and NC Highway 105 Bypass (SR-1107).  The shares some overlap with [[U.S. Route 221 Truck (Linville-Boone, North Carolina)|US&nbsp;221 Truck]] and complete overlap with [[U.S. Route 421 Truck (Boone, North Carolina)|US&nbsp;421 Truck]].
{{Clear}}

===Greeneville truck route===
{{Infobox road small
|state=TN
|type=US-Truck
|route=321
|formed
|location=[[Greeneville, Tennessee]]
|length_mi=3.6
}}

'''U.S. Route 321 Truck''' ('''US 321 Truck''') redirects truckers traveling south on US 321 around downtown. It shares a [[concurrency (road)|concurrency]] with [[U.S. Route 11E in Tennessee|US 11E]] and [[Tennessee State Route 70|SR 70]]. The route begins at US 11E/US 321 and ends {{convert|3.6|mi|km}} later at US 321/SR 70.

{{jcttop|state=TN|county=Greene|location=Greeneville}}
{{TNint
|mile=0.0
|type=concur
|road={{jct|state=TN|US|321|TN|35|name2=West Main Street|TN|70|dir3=south|name3=Asheville Highway|Sec|107|name4=Asheville Highway / West Main Street|city1=Greeneville|city2=Parrottsville|city3=Newport|city4=Del Rio|location5=[[Asheville, North Carolina|Asheville]]}}
|notes=Southern terminus of US 321 Truck and end SR 70 overlap}}
{{TNint
|mile=1.0
|type=concur
|road={{jct|state=TN|US-Bus|11E|dab1=Greeneville|dir1=North|name1=West Summer Street|Sec|350|dir2=South|name2=West Summer Street|location1=Downtown Greeneville}}
|notes=Begin US 11E Business concurrency; Northern terminus of SR 350}}
{{TNint
|mile=1.2
|type=concur
|road={{jct|state=TN|US|11E|dir1=South|TN|34|dir2=South|name2=West Andrew Johnson Highway|city1=Mosheim|city2=Bulls Gap|city3=Morristown|road|Blue Springs Parkway}}
|notes=Southern terminus of US 11E Business; Begin US 11E/SR 34 overlap}}
{{TNint
|mile=1.7
|type=concur
|road={{jct|state=TN|TN|70|dir1=North|name1=Lonesome Pine Trail|city1=Romeo|city2=Rogersville}}
|notes=End SR 70 overlap}}
{{TNint
|mile=2.0
|road={{jct|state=TN|Sec|172|dir1=North|name1=Baileyton Road|road|WhiteHouse Road|city1=Baileyton|location2=[[Greeneville-Greene County Municipal Airport|Airport]]}}
|notes=Southern terminus of SR 172; Interchange}}
{{TNint
|mile=3.4
|type=concur
|road={{jct|state=TN|US|11E|dir1=North|US|321|name2=North Main Street / East Andrew Johnson Highway|TN|34|dir3=North|name3=East Andrew Johnson Highway|TN|35|dir4=South|name4=North Main Street|city1=Jonesborough|city2=Johnson City|city3=Newport|location4=Downtown Greeneville}}
|notes=End US 321 Truck}}
{{TNint
|mile=3.6
|road={{jct|state=TN|TN|93|dir1=North|name1=Kingsport Highway|city1=Fall Branch|city2=Kingsport}}
|notes=Southern terminus of SR 93}}
{{jctbtm|keys=concur}}

{{Clear}}

==See also==
*{{Portal-inline|U.S. roads}}

==References==
{{reflist}}
* [http://www.hickoryrecord.com/servlet/Satellite?pagename=HDR/MGArticle/HDR_BasicArticle&c=MGArticle&cid=1137834703460 "U.S. 321 widening to take longer than estimated"] by Andrew Mackie, ''Hickory Daily Record'', March 14, 2006

==External links==
{{Attached KML}}
*{{commons category-inline|U.S. Route 321}}
* [https://www.angelfire.com/sc3/scroads/us321.html Mapmikey's South Carolina Highways Page: U.S. Route 321]
* [http://www.vahighways.com/ncannex/route-log/us321.html NCRoads.com: U.S. Route 321]
* [http://www.vahighways.com/ncannex/route-log/us321a.html NCRoads.com: U.S. Route 321-A]
* [http://www.vahighways.com/ncannex/route-log/us321b.html NCRoads.com: U.S. Route 321 Business]
* [http://usends.com/321.html Endpoints of U.S. Highway 321]

{{US 21}}

[[Category:United States Numbered Highway System|21-3]]
[[Category:U.S. Highways in North Carolina|21-3]]
[[Category:U.S. Highways in South Carolina|21-3]]
[[Category:U.S. Highways in Tennessee|21-3]]
[[Category:U.S. Route 21|3]]
[[Category:Transportation in Jasper County, South Carolina]]
[[Category:Transportation in Hampton County, South Carolina]]
[[Category:Transportation in Bamberg County, South Carolina]]
[[Category:Transportation in Orangeburg County, South Carolina]]
[[Category:Transportation in Lexington County, South Carolina]]
[[Category:Transportation in Richland County, South Carolina]]
[[Category:Transportation in Fairfield County, South Carolina]]
[[Category:Transportation in Chester County, South Carolina]]
[[Category:Transportation in York County, South Carolina]]
[[Category:Transportation in Gaston County, North Carolina]]
[[Category:Transportation in Lincoln County, North Carolina]]
[[Category:Transportation in Catawba County, North Carolina]]
[[Category:Transportation in Burke County, North Carolina]]
[[Category:Transportation in Caldwell County, North Carolina]]
[[Category:Transportation in Watauga County, North Carolina]]
[[Category:Transportation in Avery County, North Carolina]]
[[Category:Transportation in Johnson County, Tennessee]]
[[Category:Transportation in Carter County, Tennessee]]
[[Category:Transportation in Washington County, Tennessee]]
[[Category:Transportation in Greene County, Tennessee]]
[[Category:Transportation in Cocke County, Tennessee]]
[[Category:Transportation in Sevier County, Tennessee]]
[[Category:Transportation in Blount County, Tennessee]]
[[Category:Transportation in Loudon County, Tennessee]]