View source for Ottawa River

{{short description|River in Canada}}
{{About|the river in Canada}}
{{Use Canadian English|date=August 2019}}
{{Infobox river
| name               = Ottawa River
| name_native        = 
| name_native_lang   = 
| name_other         = {{native name|fr|Rivière des Outaouais}}<br />{{native name|alq|Kichi-Sìbì}}
| name_etymology     = 
<!---------------------- IMAGE & MAP -->
| image              = Ottawa-River.JPG
| image_caption      = The Ottawa River in autumn
| image_size         = 270px
| map                = Ottawarivermap.png
| map_size           = 270px
| map_caption        = Map of the [[Ottawa River drainage basin]]
| pushpin_map        = 
| pushpin_map_size   = 
| pushpin_map_caption= 
<!---------------------- LOCATION -->
| subdivision_type1  = Country
| subdivision_name1  = Canada
| subdivision_type2  = 
| subdivision_name2  = 
| subdivision_type3  = Provinces
| subdivision_name3  = [[Quebec]], [[Ontario]]
| subdivision_type4  = 
| subdivision_name4  = 
| subdivision_type5  = 
| subdivision_name5  = 
<!---------------------- PHYSICAL CHARACTERISTICS -->
| length             = {{cvt|1271|km}}<ref name="atlas"/>
| width_min          = 
| width_avg          = 
| width_max          = {{cvt|7,400|m}}<ref name=cbcnum/>
| depth_min          = 
| depth_avg          = 
| depth_max          = {{cvt|90|m}}<ref name=cbcnum/>
| discharge1_location= Carillon dam
| discharge1_min     = {{cvt|749|m3/s}}
| discharge1_avg     = {{cvt|1950|m3/s}}<ref name="atlas"/>
| discharge1_max     = {{cvt|5351|m3/s}}
<!---------------------- BASIN FEATURES -->
| source1            = Lac des Outaouais
| source1_location   = [[Lac-Moselle, Quebec|Lac-Moselle]], [[La Vallée-de-la-Gatineau Regional County Municipality, Quebec|La Vallée-de-la-Gatineau RCM]], [[Outaouais]], Quebec, Canada
| source1_coordinates= {{coord|47|38|38|N|75|38|35|W}}
| source1_elevation  = 
| mouth              = [[St. Lawrence River]]
| mouth_location     = [[Montreal]], Quebec and [[Ottawa]], Ontario, Canada
| mouth_coordinates  = {{coord|45|27|N|74|05|W|region:CA-QC_dim:100km|display=inline,title}}
| mouth_elevation    = 
| progression        = {{PSaint Lawrence}}
| river_system       = [[Saint Lawrence River]] [[drainage basin]]
| basin_size         = {{cvt|146300|km2}}<ref name="atlas"/>
| tributaries_left   = 
| tributaries_right  = 
| custom_label       = 
| custom_data        = 
| mapframe          = yes
| mapframe-zoom     = 5
| mapframe-wikidata = yes
| mapframe-point    = none
}}

The '''Ottawa River''' ({{langx|fr|Rivière des Outaouais}}, {{langx|alq|Kichi-Sìbì/Kitchissippi}}) is a [[river]] in the Canadian provinces of [[Ontario]] and [[Quebec]]. It is named after the Algonquin word "to trade", as it was the major trade route of Eastern Canada at the time. For most of its length, it defines the border between these two provinces. It is a major tributary of the [[St. Lawrence River]] and the longest river in Quebec.

==Geography==
[[File:Ottawa River from satellite.jpg|thumb|left|In this [[false-colour]] satellite image, the Ottawa River flows southeast, joining the St. Lawrence River which flows northeast. Heavily forested areas appear differing shades of orange/red, while farmland is tan shades.]]

The river rises at Lac des Outaouais, north of the [[Laurentian Mountains]] of central Quebec, and flows west to [[Lake Timiskaming]]. From there its route has been used to define the interprovincial border with Ontario. 

From Lake Timiskaming, the river flows southeast to [[Ottawa]] and [[Gatineau]], where it tumbles over [[Chaudière Falls]] and further takes in the [[Rideau River|Rideau]] and [[Gatineau River|Gatineau]] rivers.

The Ottawa River drains into the [[Lake of Two Mountains]] and the St. Lawrence River at [[Montreal]].  The river is {{cvt|1271|km}} long; it drains an area of {{cvt|146300|km2}}, 65&nbsp;per cent in Quebec and the rest in Ontario, with a mean discharge of {{cvt|1950|m3/s}}.<ref name="atlas">{{cite web |url=http://atlas.nrcan.gc.ca/site/english/learningresources/facts/rivers.html |title=Facts about Canada: Rivers |publisher=Natural Resources Canada/Atlas of Canada |access-date=2008-02-24 |url-status=dead |archive-url=https://web.archive.org/web/20130122002203/http://atlas.nrcan.gc.ca/site/english/learningresources/facts/rivers.html |archive-date=2013-01-22}}</ref> It has a maximum depth of {{cvt|90|m}} at the Carillon Reservoir and is {{cvt|7,400|m}} wide at its widest part.<ref name=cbcnum>{{cite news| url=https://www.cbc.ca/news/canada/ottawa/the-ottawa-river-by-the-numbers-1.750814 |title=The Ottawa River: By the Numbers | website=CBC|date=October 16, 2008|access-date=May 9, 2022}}</ref>

The average annual mean waterflow measured at [[Carillon generating station|Carillon dam]], near the Lake of Two Mountains, is {{cvt|1939|m3/s}}, with average annual extremes of {{cvt|749|to|5351|m3/s}}. Record historic levels since 1964 are a low of {{cvt|467|m3/s}} in 2010 and a high of {{cvt|9094|m3/s}} in 2017.<ref name="orrpb">{{cite web |url=http://ottawariver.ca/information/historical-water-level-streamflow-summary/ottawa-river-at-carillon/ |title=Monthly and Annual Mean Water Levels in Metres From 1950, Ottawa River at Carillon |publisher=Ottawa River Regulation Planning Board |access-date=2020-06-23}}</ref>

The river flows through large areas of deciduous and coniferous forest formed over thousands of years as trees recolonized the Ottawa Valley after the ice age.<ref>Anderson, T.W. 1989. Vegetation changes over 12000 years. Geos (3) 39-47.</ref> Generally, the coniferous forests and blueberry bogs occur on old sand plains left by retreating glaciers, or in wetter areas with clay substrate. The deciduous forests, dominated by birch, maple, beech, oak and ash occur in more mesic areas with better soil, generally around the boundary with the La Varendrye Park.<ref>Braun, E.L. 1950. Deciduous Forests of Eastern North America. The Blakiston Co., Philadelphia, PA.</ref><ref name="Keddy, P.A 2008">Keddy, P.A. 2008. Earth, Water, Fire. An Ecological Profile of Lanark County. General Store Publishing House, Renfrew, Ontario. (revised from first edition 1999).</ref> These primeval forests were occasionally affected by natural fire, mostly started by lightning, which led to increased reproduction by pine and oak, as well as fire barrens and their associated species.<ref>Catling, P. and V. Brownell. 1999. Pages 392-405 in the book Anderson, R.C., J.S. Fralish and J.M. Baskin. 1999. Savannas, Barrens, and Rock Outcrop Plant Communities of North America.  Cambridge University Press, Cambridge, UK.</ref>  The vast areas of pine were exploited by early loggers.<ref>Hughson, J.W. and C.C. J. Bond. 1965. Hurling Down the Pine. The Historical Society of the Gatineau, Old Chelsea, Quebec. First edition 1964, Revised second edition 1965.</ref> Later generations of logging removed [[Tsuga|hemlock]] for use in tanning leather, leaving a permanent deficit of hemlock in most forests.<ref>Keddy, C.J. 1993. Forest History of Eastern Ontario. Prepared for the Eastern Ontario Model Forest Group, Kemptville</ref> Associated with the logging and early settlement were vast wild fires which not only removed the forests, but led to soil erosion.<ref>Howe, C.D. 1915. The effect of repeated forest fires upon the reproduction of commercial species in Peterborough County, Ontario. Pages 116-211 in Forest Protection in Canada, 1913 1914, Commission of Conservation of Canada, William Briggs, Toronto.</ref> Consequently, nearly all the forests show varying degrees of human disturbance. Tracts of older forest are uncommon, and hence they are considered of considerable importance for conservation.<ref>Henry, M. and P. Quinby. 2009. Ontario Old Growth Forests. Fitzhenry and Whiteside, Markham, Ontario</ref>

The Ottawa River has large areas of wetlands.  Some of the more biologically important wetland areas include (going downstream from Pembroke), the Westmeath sand dune/wetland complex, Mississippi Snye, Breckenridge Nature Reserve, Shirleys Bay, Ottawa Beach/Andrew Haydon Park, Petrie Island, the Duck Islands<ref>Darbyshire, S.J. 1981. Upper Duck and Lower Duck Islands. Trail and Landscape 15:133-139.</ref> and Greens Creek.<ref name="Brunton, D.F 1992">Brunton, D.F. 1992. Life Science Areas of Natural and Scientific Interest in Site District 6-12. A Review and Assessment of Significant Natural Areas. Report prepared for Ontario Ministry of Natural Resources, Kemptville, Ontario.</ref><ref>[http://ottawariverkeeper.ca/river/ecosystem_diversity/ Ecosystem Diversity] {{Webarchive|url=https://web.archive.org/web/20120424055059/http://ottawariverkeeper.ca/river/ecosystem_diversity/ |date=2012-04-24 }}. ottawariverkeeper.ca. Retrieved on 2013-07-12.</ref>  The [[Westmeath Provincial Park|Westmeath sand dune/wetland complex]] is significant for its relatively pristine sand dunes, few of which remain along the Ottawa River, and the many associated rare plants. Shirleys Bay has a biologically diverse shoreline alvar, as well as one of the largest silver maple swamps along the river.  Like all wetlands, these depend upon the seasonal fluctuations in the water level.<ref>Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK</ref>  High water levels help create and maintain [[Acer saccharinum|silver maple]] swamps,<ref>Toner, M, and P. Keddy. 1997. River hydrology and riparian wetlands: a predictive model for ecological assembly. Ecological Applications 7: 236-246</ref> while low water periods allow many rare wetland plants to grow on the emerged sand and clay flats.<ref>Brunton, D.F. and B.M. Di Labio. Diversity and ecological characteristics of emergent beach flora along the Ottawa River in the Ottawa-Hull region, Quebec and Ontario. Naturaliste canadien 116: 179-191.</ref>  There are five principal wetland vegetation types.  One is swamp, mostly silver maple.  There are four herbaceous vegetation types, named for the dominant plant species in them: ''Scirpus'', ''Eleocharis'', ''Sparganium'' and ''Typha''.<ref>Day, R., P.A. Keddy, J. McNeill and T. Carleton.  1988.  Fertility and disturbance gradients:  a summary model for riverine marsh vegetation.  Ecology 69:1044-1054</ref>  Which type occurs in a particular location depends upon factors such as substrate type, water depth, ice-scour and fertility. Inland, and mostly south of the river, older river channels, which date back to the end of the ice age, and no longer have flowing water, have sometimes filled with a different wetland type, peat bog.  Examples include Mer Bleue and Alfred Bog.<ref name="Brunton, D.F 1992"/>

===Tributaries===
Major tributaries include:
{{colbegin|colwidth=26em}}
* [[Bonnechere River]]
* [[Coulonge River]]
* [[Dumoine River]]
* [[Gatineau River]]
* [[Kipawa River]]
* [[du Lièvre River]]
* [[Madawaska River (Ontario)|Madawaska River]]
* [[Mattawa River]]
* [[Mississippi River (Ontario)|Mississippi River]]
* [[Montreal River (Timiskaming District)|Montreal River]]
* [[Rivière du Nord (Laurentides)|Rivière du Nord]]
* [[Noire River (Ottawa River tributary)|Noire River]]
* [[Petawawa River]]
* [[Rideau River]]
* [[Rouge River (Quebec)|Rouge River]]
* [[South Nation River]]
{{colend}}

===Communities===
[[File:River Ottawa (view from the Peace Tower of Parliament Centre Block).JPG|thumb|Ottawa River, looking upstream (view from the Peace Tower of Parliament Centre Block)]]
[[File:River Ottawa (view from the Peace Tower of Parliament Centre Block) 2.JPG|thumb|Ottawa River, looking downstream (view from the Peace Tower of Parliament Centre Block)]]
Communities along the Ottawa River include (in down-stream order): <!-- NOT municipalities -->
{{colbegin|colwidth=26em}}
*[[Kitcisakik Anicinape Community]]
*[[Winneway|Long Point First Nation]]
*[[Moffet, Quebec]]
*[[Laverlochère-Angliers|Angliers, Quebec]]
*[[Notre-Dame-du-Nord, Quebec]]
*[[Timiskaming First Nation]]
*[[Temiskaming Shores, Ontario]]
*[[Ville-Marie, Quebec]]
*[[Témiscaming, Quebec]]
*[[Thorne, Ontario]]
*[[Mattawa, Ontario]]
*[[Head, Clara and Maria|Deux Rivières, Ontario]]
*[[Rapides-des-Joachims, Quebec]]
*[[Laurentian Hills|Rolphton, Ontario]]
*[[Deep River, Ontario]]
*[[Sheenboro, Quebec]]
*[[Petawawa, Ontario]]
*[[Pembroke, Ontario]]
*[[Whitewater Region|Westmeath, Ontario]]
*[[Waltham, Quebec]]
*[[Mansfield-et-Pontefract|Davidson, Quebec]]
*[[Fort-Coulonge, Quebec]]
*[[Whitewater Region, Ontario|La Passe, Ontario]]
*[[Campbell's Bay, Quebec]]
*[[Bryson, Quebec]]
*[[Portage-du-Fort, Quebec]]
*[[Bristol, Quebec]]
*[[Norway Bay, Quebec]]
*[[McNab/Braeside|Braeside, Ontario]]
*[[Arnprior, Ontario]]
*[[Fitzroy Harbour, Ontario]]
*[[Quyon, Quebec]]
*[[Constance Bay, Ontario]]
*[[Aylmer, Quebec]]
*[[Ottawa|Ottawa, Ontario]]
*[[Gatineau|Gatineau, Quebec]]
*[[Masson-Angers, Quebec]]
*[[Cumberland, Ottawa|Cumberland, Ontario]]
*[[Rockland, Ontario]]
*[[Thurso, Quebec]]
*[[Alfred and Plantagenet|Wendover, Ontario]]
*[[Plaisance, Quebec]]
*[[Papineauville, Quebec]]
*[[Montebello, Quebec]]
*[[Fassett, Quebec]]
*[[L'Orignal, Ontario]]
*[[Grenville, Quebec]]
*[[Hawkesbury, Ontario]]
*[[Saint-André-d'Argenteuil|Carillon, Quebec]]
*[[Pointe-Fortune, Quebec]]
*[[Saint-André-d'Argenteuil|Saint-André-Est, Quebec]]
*[[Rigaud, Quebec]]
*[[Saint-Placide, Quebec]]
*[[Kanesatake]]
*[[Hudson, Quebec]]
*[[Oka, Quebec]]
*[[Vaudreuil-sur-le-Lac, Quebec]]
*[[L'Île-Cadieux|L'Île-Cadieux, Quebec]]
*[[Vaudreuil-Dorion|Vaudreuil-Dorion, Quebec]]
*[[Terrasse-Vaudreuil, Quebec]]
*[[Pincourt, Quebec]]
*[[Pointe-des-Cascades, Quebec]]
{{colend}}

===Islands===
====Ontario====
{{Div col|colwidth=16em}}
* [[Alexandra Island]]<ref>{{Cite cgndb|FACHM|name=Alexandra Island}}</ref>
* [[Aylmer Island]]<ref>{{Cite cgndb|FEGAQ|name=Aylmer Island}}</ref>
* [[Basil Island (Ottawa River)|Basil Island]]<ref>{{Cite cgndb|FAFJY|name=Basil Island}}</ref>
* [[Bate Island]]<ref>{{Cite cgndb|FEGJM|name=Bate Island}}</ref>
* [[Beacon Island (Ottawa River)|Beacon Island]]<ref>{{Cite cgndb|FAFQI|name=Beacon Island}}</ref> 
* [[Beckett Island]]<ref>{{Cite cgndb|FAGNZ|name=Beckett Island}}</ref>
* [[Bell Island (Ottawa River)|Bell Island]]<ref>{{Cite cgndb|FAGYB|name=Bell Island}}</ref>
* [[Big Island (Ottawa River)|Big Island]]<ref>{{Cite cgndb|FAHZT|name=Big Island}}</ref>
* [[Big Elbow Island]]<ref>{{Cite cgndb|FAHWT|name=Big Elbow Island}}</ref>
* [[Bruyère Island]]<ref>{{Cite cgndb|FAMIA|name=Bruyère Island}}</ref>
* [[Burnt Island (Ottawa River)|Burnt Island]]<ref>{{Cite cgndb|FANAW|name=Burnt Island}}</ref>
*[[Butternut Island]]<ref>{{Cite cgndb|FANLP|name=Butternut Island}}</ref>
* [[Carl Island]]<ref>{{Cite cgndb|FAOXA|name=Carl Island}}</ref> 
* [[Cedar Island (Ottawa River)|Cedar Island]]<ref>{{Cite cgndb|FAPLC|name=Cedar Island}}</ref>
* [[Chapman Island]]<ref>{{Cite cgndb|FAPYC|name=Chapman Island}}</ref> 
* [[Chartrand Island]]<ref>{{Cite cgndb|FAQCH|name=Chartrand Island}}</ref>
* [[Chenaux Island]]<ref>{{Cite cgndb|FAQCH|name=Chenaux Island}}</ref>
*[[Christie Island (Ontario)|Christie Island]]<ref>{{Cite cgndb|FAQST|name=Christie Island}}</ref> 
* [[Clarence Island (Ontario)|Clarence Island]]<ref>{{Cite cgndb|FAQGV|name=Clarence Island}}</ref>
* [[Coreille Island]]<ref>{{Cite cgndb|FATCQ|name=Coreille Island}}</ref>
* [[Corinne Island]]<ref>{{Cite cgndb|FATCZ|name=Corinne Island}}</ref> 
* [[Cornelius Island (Ottawa River)|Cornelius Island]]<ref>{{Cite cgndb|FATEV|name=Cornelius Island}}</ref> 
* [[Cotnam Island]]<ref>{{Cite cgndb|FATJT|name=Cotnam Island}}</ref>
*[[Crab Islands]]<ref>{{Cite cgndb|FATSO|name=Crab Islands}}</ref> 
* [[Cunningam Island (Ontario)|Cunningam Island]]<ref>{{Cite cgndb|FAUYG|name=Cunningham Island}}</ref>
* [[Cushing Island (Ontario)|Cushing Island]]<ref>{{Cite cgndb|FAVAT|name=Cushing Island}}</ref>
*[[Daisy Island]]<ref>{{Cite cgndb|FAVEL|name=Daisy Island}}</ref> 
* [[Davis Island (Ottawa River)|Davis Island]]<ref>{{Cite cgndb|FAVOT|name=Davis Island}}</ref>
* [[Deep River Islet]]<ref>{{Cite cgndb|FAWAO|name=Deep River Islet}}</ref>
* [[Demers Island (Ontario)|Demers Island]]<ref>{{Cite cgndb|FAWIM|name=Demers Island}}</ref> 
* [[Dow Island]]<ref>{{Cite cgndb|FAZOL|name=Dow Island}}</ref> 
* [[Dunlop Island (Ottawa River)|Dunlop Island]]<ref>{{Cite cgndb|FBAMQ|name=Dunlop Island}}</ref> 
* [[Dupras Island]]<ref>{{Cite cgndb|FBAOZ|name=Dupras Island}}</ref>
*[[Dutch Island (Ontario)|Dutch Island]]<ref>{{Cite cgndb|FBARC|name=Dutch Island}}</ref>
* [[Ellis Island (Ontario)|Ellis Island]]<ref>{{Cite cgndb|FBCHY|name=Ellis Island}}</ref> 
* [[Evelyn Island]]<ref>{{Cite cgndb|FBDCU|name=Evelyn Island}}</ref> 
* [[Farr Island]]<ref>{{Cite cgndb|FBDQN|name=Farr Island}}</ref>
* [[Fish Island (Ottawa River)|Fish Island]]<ref>{{Cite cgndb|FEIFY|name=Fish Island}}</ref>
* [[Fraser Island (Ottawa River)|Fraser Island]]<ref>{{Cite cgndb|FBFPO|name=Fraser Island}}</ref> 
* [[Fury Island]]<ref>{{Cite cgndb|FBGEV|name=Fury Island}}</ref> 
* [[Gibraltar Island (Ottawa River)|Gibraltar Island]]<ref>{{Cite cgndb|FBHGC|name=Gibraltar Island}}</ref> 
* [[Green Island (Ottawa River)|Green Island]]<ref>{{Cite cgndb|FBJRX|name=Green Island}}</ref> 
*[[Gutzman Island]]<ref>{{Cite cgndb|FBKVT|name=Gutzman Island}}</ref>
* [[Hamilton Island (Ottawa River)|Hamilton Island]]<ref>{{Cite cgndb|FBLKE|name=Hamilton Island}}</ref>
* [[Haycock Island (Ontario)|Haycock Island]]<ref>{{Cite cgndb|FBMNQ|name=Haycock Island}}</ref>
* [[Hazel Island]]<ref name="fdwok1">{{Cite cgndb|FDWOK|name=Morris Island}}</ref> 
* [[Hazelton Island]]<ref>{{Cite cgndb|FBMQU|name=Hazel Island}}</ref>
* [[Hen Island (Ottawa River)|Hen Island]]<ref>{{Cite cgndb|FBNCR|name=Hen Island}}</ref>
* [[Hog Island (Ottawa River)|Hog Island]]<ref>{{Cite cgndb|FBOFN|name=Hog Island}}</ref>
* [[Houston Island]]<ref>{{Cite cgndb|FBPDN|name=Houston Island}}</ref> 
* [[Île Chénier]]<ref>{{Cite cgndb|FAQHH|name=Ile Chénier}}</ref>
* [[Île du Chenail]]<ref>{{Cite cgndb|FAQGP|name=Ile du Chenail}}</ref>
* [[Île Ste-Rosalie]]<ref>{{Cite cgndb|FDSYX|name=Ile Ste-Rosalie}}</ref>
* [[Île Young]]
* [[Irving Island (Ottawa River)|Irving Island]]<ref>{{Cite cgndb|FBQOS|name=Irving Island}}</ref> 
* [[Jamieson Island]]<ref>{{Cite cgndb|FBRHT|name=Jamieson Island}}</ref> 
*[[John Joe Island]]<ref>{{Cite cgndb|FBSBB|name=John Joe Island}}</ref> 
* [[Kate Island (Ontario)|Kate Island]]<ref>{{Cite cgndb|FBTEZ|name=Kate Island}}</ref> 
* [[Kedey's Island]]<ref>{{Cite cgndb|FBTMO|name=Kedey's Island}}</ref>
* [[King Edward Island]]<ref>{{Cite cgndb|FBUQR|name=King Edward Island}}</ref>
* [[Latour Island]]<ref>{{Cite cgndb|FBWMO|name=Latour Island}}</ref> 
* [[Lemieux Island]]<ref>{{Cite cgndb|FBXEA|name=Lemieux Island}}</ref> 
* [[Lillian Island]]<ref>{{Cite cgndb|FBXNV|name=Lillian Island}}</ref> 
* [[Lorne Island]]<ref>{{Cite cgndb|FCBDZ|name=Lorne Island}}</ref>
* [[Louise Island (Ottawa River)|Louise Island]]<ref>{{Cite cgndb|FCBLV|name=Louise Island}}</ref> 
* [[Lower Duck Island]]<ref>{{Cite cgndb|FCBQR|name=Lower Duck Island}}</ref>
* [[Lumpy Denommee's Island]]
* [[Mackie Island]]<ref>{{Cite cgndb|FCCSL|name=Mackie Island}}</ref> 
* [[Man Island (Ontario)|Man Island]]<ref>{{Cite cgndb|FDKLF|name=Man Island}}</ref>
* [[Meadow Island]]<ref>{{Cite cgndb|FDQTU|name=Meadow Island}}</ref>
* [[Merrill Island ]]<ref>{{Cite cgndb|FEBSY|name=Merrill Island}}</ref>
*[[Metcalf Island]]<ref>{{Cite cgndb|FEBUK|name=Metcalf Island}}</ref> 
* [[Miller Island (Ottawa River)|Miller Island]]<ref>{{Cite cgndb|FDUDX|name=Miller Island}}</ref> 
* [[Morris Island (Ottawa)|Morris Island]]<ref name="fdwok1"/>
* [[Nichol's Island]]
* [[Oak Island (Ottawa River)|Oak Island]]<ref>{{Cite cgndb|FCGJC|name=Oak Island}}</ref> 
* [[O'Meara Island]]<ref>{{Cite cgndb|FDLJF|name=O'Meara Island}}</ref> 
* [[Parker Island (Ottawa River)|Parker Island]]<ref>{{Cite cgndb|FDRSU|name=Parker Island}}</ref> 
* [[Pearl Island (Ottawa River)|Pearl Island]]<ref>{{Cite cgndb|FCHLW|name=Pearl Island}}</ref> 
* [[Petrie Island]]
* [[Pink Island]]<ref>{{Cite cgndb|FDTJQ|name=Pink Island}}</ref> 
* [[Poker Island]]<ref>{{Cite cgndb|FDZXM|name=Poker Island}}</ref> 
* [[Princess Island (Ottawa River)|Princess Island]]<ref>{{Cite cgndb|FCINR|name=Princess Island}}</ref>
* [[Ramsey Island (Ontario)|Ramsey Island]]<ref>{{Cite cgndb|FCJMH|name=Ramsey Island}}</ref>
* [[Randolph Island]]<ref>{{Cite cgndb|FCJND|name=Randolph Island}}</ref> 
* [[Rempnouix Island]]<ref>{{Cite cgndb|FCKOW|name=Rempnouix Island}}</ref> 
* [[Riopelle Island]]<ref>{{Cite cgndb|FCLDY|name=Riopelle Island}}</ref>
* [[Rocher Capitaine Island]]<ref>{{Cite cgndb|FDVSD|name=Rocher Capitaine Island}}</ref>
* [[Ruby Islet]]<ref>{{Cite cgndb|FCMUX|name=Ruby Islet}}</ref> 
* [[Sack's Island]]<ref>{{Cite cgndb|FCNGV|name=Sack's Island}}</ref>
* [[Sandbar Island]]<ref>{{Cite cgndb|FDTVC|name=Sandbar Island}}</ref>
* [[Santa Island]]<ref>{{Cite cgndb|FEAQS|name=Santa Island}}</ref>
* [[Sawlog Island]]<ref>{{Cite cgndb|FEAWK|name=Sawlog Island}}</ref>
* [[Shoal Island]]<ref>{{Cite cgndb|FCNVZ|name=Shoal Island}}</ref> 
* [[Short Turn Island]]<ref>{{Cite cgndb|FCNYY|name=Short Turn Island}}</ref> 
* [[Steamer Island]]<ref>{{Cite cgndb|FCSDS|name=Steamer Island}}</ref>
*[[Snake Island (Ottawa River)|Snake Island]]<ref>{{Cite cgndb|FERHR|name=Snake Island}}</ref> 
* [[Sullivan Island (Ottawa River)|Sullivan Island]]<ref>{{Cite cgndb|FCTRT|name=Sullivan Island}}</ref>
* [[Upper Duck Island]]<ref>{{Cite cgndb|FCYZZ|name=Upper Duck Island}}</ref>
* [[Victoria Island (Ottawa River)|Victoria Island]]<ref>{{Cite cgndb|FCZXM|name=Victoria Island}}</ref>
* [[Wabewawa Island]]<ref>{{Cite cgndb|FDAHQ|name=Wabewawa Island}}</ref> 
* [[Willson Island]]<ref>{{Cite cgndb|FDEAM|name=Willson Island}}</ref>
*[[Windsor Island]]<ref>{{Cite cgndb|FDEGZ|name=Windsor Island}}</ref> 
{{Div col end}}

====Quebec====
{{Div col|colwidth=16em}}
*[[L'Île (Laurentides)|L'Île]]<ref>{{Cite cgndb|EKLYH|name=L'Île}}</ref>
*[[Île Allen]]<ref>{{Cite cgndb|EKLKE|name=Île Allen}}</ref>
*[[Île aux Allumettes]]<ref>{{Cite cgndb|EKIEC|name=Île aux Allumettes}}</ref>
*[[Île Armstrong]]<ref>{{Cite cgndb|EFIZT|name=Île Armstrong}}</ref>
*[[Île Avelle]]<ref>{{Cite cgndb|EFJXY|name=Île Avelle}}</ref>
*[[Bald Rock (Quebec)|Bald Rock]]<ref>{{Cite cgndb|EIYQB|name=Bald Rock}}</ref>
*[[Île Béique]]<ref>{{Cite cgndb|EFMHG|name=Île Béique}}</ref>
*[[Îles Benny]]<ref>{{Cite cgndb|EKHZF|name=Îles Benny}}</ref>
*[[Île Bernard]]<ref>{{Cite cgndb|EIOCH|name=Île Bernard}}</ref>
*[[Île Bernardin]]<ref>{{Cite cgndb|EPHGT|name=Île Bernardin}}</ref>
*[[Île Berry]]<ref>{{Cite cgndb|EFNCA|name=Île Berry}}</ref>
*[[Île à Bertrand]]<ref>{{Cite cgndb|EKIBO|name=Île à Bertrand}}</ref>
*[[Île Boom]]<ref>{{Cite cgndb|EFPFR|name=Île Boom}}</ref>
*[[Île Bray]]<ref>{{Cite cgndb|EQJOG|name=Île Bray}}</ref>
*[[Île Brisseau]]<ref>{{Cite cgndb|EFQXQ|name=Île Brisseau}}</ref>
*[[Île Brunet]]<ref>{{Cite cgndb|EKLPA|name=Île Brunet}}</ref>
*[[Île Bryson]]<ref>{{Cite cgndb|EFRQY|name=Île Bryson}}</ref>
*[[Île Cadieux]]<ref>{{Cite cgndb|EFSKK|name=Île Cadieux}}</ref>
*[[Île Cobb]]<ref>{{Cite cgndb|EKIBG|name=Île Cobb}}</ref>
*[[Île de Carillon]]<ref>{{Cite cgndb|EFTWT|name=Île de Carillon}}</ref>
*[[Île du Centre]]<ref>{{Cite cgndb|EKLJP|name=Île du Centre}}</ref>
*[[Île du Chef]]<ref>{{Cite cgndb|EFWRM|name=Île du Chef}}</ref>
*[[Île du Chenal Blind]]<ref>{{Cite cgndb|EIYQR|name=Île du Chenal Blind}}</ref>
*[[Île du Chicot]]<ref>{{Cite cgndb|EKISF|name=Île du Chicot}}</ref>
*[[Îles à Cole]]<ref>{{Cite cgndb|EKISE|name=Îles à Cole}}</ref>
*[[Île du Collège]]<ref>{{Cite cgndb|EFYUI|name=Île du Collège}}</ref>
*[[Île de la Compagnie]]<ref>{{Cite cgndb|EMHFV|name=Île de la Compagnie}}</ref>
*[[Île à Cowley]]<ref>{{Cite cgndb|EKIRM|name=Île à Cowley}}</ref>
*[[Île à Crépault]]<ref>{{Cite cgndb|EKLZS|name=Île à Crépault}}</ref>
*[[Île D'Arcy]]<ref>{{Cite cgndb|EGBXW|name=Île D'Arcy}}</ref>
*[[Île Davidson]]<ref>{{Cite cgndb|EKIBS|name=Île Davidson}}</ref>
*[[Île Dog]]<ref>{{Cite cgndb|EMHIA|name=Île Dog}}</ref>
*[[Île Dubé]]<ref>{{Cite cgndb|EGEVE|name=Île Dubé}}</ref>
*[[Île à Everill]]<ref>{{Cite cgndb|EKITI|name=Île à Everill}}</ref>
*[[Île Fer à Cheval]]<ref>{{Cite cgndb|EGIOS|name=Île Fer à Cheval}}</ref>
*[[Île du Finlandais]]<ref>{{Cite cgndb|EOHHR|name=Île du Finlandais}}</ref>
*[[Îles Finlay]]<ref>{{Cite cgndb|EGIZT|name=Îles Finlay}}</ref>
*[[Île Fitzpatrick]]<ref>{{Cite cgndb|EGJCH|name=Île Fitzpatrick}}</ref>
*[[Île au Foin]]<ref>{{Cite cgndb|EKLVN|name=Île au Foin}}</ref>
*[[Île Fox (Pontiac)]]<ref>{{Cite cgndb|EGKGR|name=Île Fox}}</ref>
*[[Île Fox (Témiscamingue)]]<ref>{{Cite cgndb|EGKGT|name=Île Fox}}</ref>
*[[Île French]]<ref>{{Cite cgndb|EGKSI|name=Île French}}</ref>
*[[Île Frigon]]<ref>{{Cite cgndb|EGKUF|name=Île Frigon}}</ref>
*[[Île Gagnon]]<ref>{{Cite cgndb|EGLDS|name=Île Gagnon}}</ref>
*[[Rocher à Gillis]]<ref>{{Cite cgndb|EKIUE|name=Rocher à Gillis}}</ref>
*[[Rochers aux Goélands]]<ref>{{Cite cgndb|EGNFP|name=Rochers aux Goélands}}</ref>
*[[Île Graham]]<ref>{{Cite cgndb|EPHGS|name=Île Graham}}</ref>
*[[Île du Grand Calumet]]<ref>{{Cite cgndb|EGNSV|name=Île du Grand Calumet}}</ref>
*[[Île Green]]<ref>{{Cite cgndb|EJBLQ|name=Île Green}}</ref>
*[[Île Greene]]<ref>{{Cite cgndb|EKLJR|name=Île Greene}}</ref>
*[[Île à Griffin]]<ref>{{Cite cgndb|EKITW|name=Île à Griffin}}</ref>
*[[Île Harbec]]<ref>{{Cite cgndb|EKLPB|name=Île Harbec}}</ref>
*[[Île Hemlock]]<ref>{{Cite cgndb|EKIVR|name=Île Hemlock}}</ref>
*[[Île Henry]]<ref>{{Cite cgndb|EKIEJ|name=Île Henry}}</ref>
*[[Île Hiam]]<ref>{{Cite cgndb|EGQTG|name=Île Hiam}}</ref>
*[[Île Jacey]]<ref>{{Cite cgndb|EGSZI|name=Île Jacey}}</ref>
*[[Île John-Park]]<ref>{{Cite cgndb|EKIEE|name=Île John-Park}}</ref>
*[[Île Jones]]<ref>{{Cite cgndb|EGUFG|name=Île Jones}}</ref>
*[[Îles Jumelles]]<ref>{{Cite cgndb|EGUQI|name=Îles Jumelles}}</ref>
*[[Île Kettle]]<ref>{{Cite cgndb|EGVKB|name=Île Kettle}}</ref>
*[[Île Lafleur]]<ref>{{Cite cgndb|EKLSW|name=Île Lafleur}}</ref>
*[[Île Lafontaine]]<ref>{{Cite cgndb|EGWSP|name=Île Lafontaine}}</ref>
*[[Île Lasalle]]<ref>{{Cite cgndb|EIQPQ|name=Île Lasalle}}</ref>
*[[Île à Lawn]]<ref>{{Cite cgndb|EKIVX|name=Île à Lawn}}</ref>
*[[Île Leblanc]]<ref>{{Cite cgndb|EGYRA|name=Île Leblanc}}</ref>
*[[Île Lemoine]]<ref>{{Cite cgndb|EKHZS|name=Île Lemoine}}</ref>
*[[Île Leroux]]<ref>{{Cite cgndb|EKLPC|name=Île Leroux}}</ref>
*[[Île Lighthouse (L'Isle-aux-Allumettes)]]<ref>{{Cite cgndb|EIQTC|name=Île Lighthouse}}</ref>
*[[Île Lighthouse (Bristol)]]<ref>{{Cite cgndb|EKLIY|name=Île Lighthouse}}</ref>
*[[Île Limerick]]<ref>{{Cite cgndb|EHAAM|name=Île Limerick}}</ref>
*[[Petite île Limerick]]<ref>{{Cite cgndb|EHAAN|name=Petite île Limerick}}</ref>
*[[Île Lorelei]]<ref>{{Cite cgndb|EHBAR|name=Île Lorelei}}</ref>
*[[Île Mann]]<ref>{{Cite cgndb|EHDEY|name=Île Mann}}</ref>
*[[Île Marcotte]]<ref>{{Cite cgndb|EKICZ|name=Île Marcotte}}</ref>
*[[Île à Marion]]<ref>{{Cite cgndb|EKIBI|name=Île à Marion}}</ref>
*[[Île Mohr]]<ref>{{Cite cgndb|EHHEQ|name=Île Mohr}}</ref>
*[[Île Morrison]]<ref>{{Cite cgndb|EHIIF|name=Île Morrison}}</ref>
*[[Île Mulligan]]<ref>{{Cite cgndb|EKLJQ|name=Île Mulligan}}</ref>
*[[Île O'Connor]]<ref>{{Cite cgndb|EKLJV|name=Île O'Connor}}</ref>
*[[Île Oscar-Béchamp]]<ref>{{Cite cgndb|EKICO|name=Île Oscar-Béchamp}}</ref>
*[[Île Oster]]<ref>{{Cite cgndb|EHMNW|name=Île Oster}}</ref>
*[[Île Paquin]]<ref>{{Cite cgndb|EHNSV|name=Île Paquin}}</ref>
*[[Île à Payne]]<ref>{{Cite cgndb|EKIXS|name=Île à Payne}}</ref>
*[[Îles Pelley]]<ref>{{Cite cgndb|EKLVH|name=Îles Pelley}}</ref>
*[[Île Philemon]]<ref>{{Cite cgndb|EHQAN|name=Île Philemon}}</ref>
*[[Île Pigs]]<ref>{{Cite cgndb|EMHQE|name=Île Pigs}}</ref>
*[[Île aux Pins]]<ref>{{Cite cgndb|EHQYP|name=Île aux Pins}}</ref>
*[[Île des Quinze]]<ref>{{Cite cgndb|EIYQX|name=Île des Quinze}}</ref>
*[[Île Rainville]]<ref>{{Cite cgndb|EHUKY|name=Île Rainville}}</ref>
*[[Île des Rapides]]<ref>{{Cite cgndb|EHURQ|name=Île des Rapides}}</ref>
*[[Île du Refuge]]<ref>{{Cite cgndb|EHVGC|name=Île du Refuge}}</ref>
*[[Île Reid (Clarendon)]]<ref>{{Cite cgndb|EHVHO|name=Île Reid}}</ref>
*[[Île Reid (L'Isle-aux-Allumettes)]]<ref>{{Cite cgndb|EHVHP|name=Île Reid}}</ref>
*[[Île Rita]]<ref>{{Cite cgndb|EHWCN|name=Île Rita}}</ref>
*[[Île à Ritté]]<ref>{{Cite cgndb|EHWDD|name=Île à Ritté}}</ref>
*[[Île du Rocher Fendu]]<ref>{{Cite cgndb|EKIYO|name=Île du Rocher Fendu}}</ref>
*[[Île à Rouleau]]<ref>{{Cite cgndb|EKIYU|name=Île à Rouleau}}</ref>
*[[Île à Roussin]]<ref>{{Cite cgndb|EKLZQ|name=Île à Roussin}}</ref>
*[[Île de Sable]]<ref>{{Cite cgndb|EHYHY|name=Île de Sable}}</ref>
*[[Petite île Sèche]]<ref>{{Cite cgndb|EKLZR|name=Petite île Sèche}}</ref>
*[[La Semelle]]<ref>{{Cite cgndb|EICSY|name=La Semelle}}</ref>
*[[Île Smith]]<ref>{{Cite cgndb|EISVN|name=Île Smith}}</ref>
*[[Île Snake]]<ref>{{Cite cgndb|EMHHW|name=Île Snake}}</ref>
*[[Île des Soeurs (Témiscamingue)|Île des Soeurs]]<ref>{{Cite cgndb|EIEDP|name=Île des Soeurs}}</ref>
*[[Île Soulier]]<ref>{{Cite cgndb|EIEKD|name=Île Soulier}}</ref>
*[[Île Squelette]]<ref>{{Cite cgndb|EIZFR|name=Île Squelette}}</ref>
*[[Île Submergée]]<ref>{{Cite cgndb|EIFDT|name=Île Submergée}}</ref>
*[[Île Sunset]]<ref>{{Cite cgndb|EIFJJ|name=Île Sunset}}</ref>
*[[Île Todd]]<ref>{{Cite cgndb|EIHMX|name=Île Todd}}</ref>
*[[Île à Tom]]<ref>{{Cite cgndb|EKIZT|name=Île à Tom}}</ref>
*[[Île à Tom-Simon]]<ref>{{Cite cgndb|EIYRA|name=Île à Tom-Simon}}</ref>
*[[Île aux Tourtes]]<ref>{{Cite cgndb|EIHYY|name=Île aux Tourtes}}</ref>
*[[Île Verte (Témiscamingue)|Île Verte]]<ref>{{Cite cgndb|EILCC|name=Île Verte}}</ref>
*[[Île Victoria]]<ref>{{Cite cgndb|EKJAG|name=Île Victoria}}</ref>
*[[Île Wickens]]<ref>{{Cite cgndb|EKJAI|name=Île Wickens}}</ref>
*[[Île Winneway]]<ref>{{Cite cgndb|EINEJ|name=Île Winneway}}</ref>
*[[Île Woods]]<ref>{{Cite cgndb|EITLH|name=Île Woods}}</ref>
*[[Île Wight]]<ref>{{Cite cgndb|EIMXQ|name=Île Wight}}</ref>
*[[Île Young (Pontiac)]]<ref>{{Cite cgndb|EIVXI|name=Île Young (Pontiac)}}</ref>
*[[Île Young (Gatineau)]]<ref>{{Cite cgndb|EJXII|name=Île Young (Gatineau)}}</ref>
*[[Île Yvette-Naubert]]<ref>{{Cite cgndb|EKZNV|name=Île Yvette-Naubert}}</ref>
{{Div col end}}

==Geology==
[[File:Ottawabonnecheregrabenmap.png|thumb|left|Map of the [[Ottawa-Bonnechere Graben]]]]
The Ottawa River lies in the [[Ottawa-Bonnechere Graben]], which is a [[Mesozoic]] [[rift valley]] that formed 175 million years ago. Much of the river flows through the Canadian Shield, although lower areas flow through limestone plains and glacial deposits.<ref name="Chapman, L.J 1984">Chapman, L.J. and D.F. Putnam. 1984. The Physiography of Southern Ontario. Third edition. Ontario Geological Survey, Special Volume No.2. Government of Ontario, Toronto.</ref>

As the [[glacier|glacial ice sheet]] began to retreat at the end of the [[last glacial period|last ice age]], the Ottawa River valley, which, along with the [[St. Lawrence River]] valley and [[Lake Champlain]], had been depressed to below [[sea level]] by the glacier's weight, filled with sea water.<ref>{{cite web |title=Champlain Sea: Phase 2 |url=http://hannover.park.org/Canada/Museum/champlain/PHASE2.HTM |website=hannover.park.org |access-date=15 December 2018 |archive-url=https://web.archive.org/web/20110809081740/http://hannover.park.org/Canada/Museum/champlain/PHASE2.HTM |archive-date=August 9, 2011}}</ref>  The resulting arm of the [[Atlantic Ocean|ocean]] is known as the [[Champlain Sea]].  Fossil remains of marine life dating 12 to 10 thousand years ago have been found in marine [[clay]] throughout the region. Sand deposits from this era have produced vast plains, often dominated by pine forests, as well as localized areas of sand dunes, such as Westmeath and Constance Bay.<ref name="Chapman, L.J 1984"/>  Clay deposits from this period have resulted in areas of poor drainage, large swamps, and peat [[bog]]s in some ancient channels of this river. Hence, the distribution of forests and wetlands is very much a product of these past glacial events.<ref name="Keddy, P.A 2008"/>

[[File:Ottawa River Stromatolite Bed.jpg|thumb|Ottawa River [[Stromatolite]] Bed, near the [[Champlain Bridge (Ottawa)]], with the Ottawa skyline in the background<ref>{{cite web |title=Paleontological Highlights |url=http://ottawariverkeeper.ca/river/paleontological_highlights/ |website=OttawaRiverKeeper.ca |access-date=December 15, 2018 |archive-url=https://web.archive.org/web/20090624014037/http://ottawariverkeeper.ca/river/paleontological_highlights/ |archive-date=June 24, 2009}}</ref>]]
Large deposits of a material commonly known as [[Quick clay|Leda clay]] also formed.  These deposits become highly unstable after heavy rains. Numerous [[landslide]]s have occurred as a result.  The former site of the town of [[Lemieux, Ontario]] collapsed into the [[South Nation River]] in 1993.  The town's residents had previously been relocated because of the suspected instability of the earth in that location.

As the land gradually [[Isostatic rebound|rose again]] the sea coast retreated and the fresh water courses of today took shape.  Following the demise of the Champlain Sea the Ottawa River  Valley continued to drain the waters of the emerging Upper Great Lakes basin through [[Lake Nipissing]] and the [[Mattawa River]]. Owing to the ongoing uplift of the land, the eastward flow became blocked around 4000 years ago. Thereafter Lake Nipissing drained westward, through the [[French River (Ontario)|French River]] which later became a link in the historic canoe route to the West.<ref>{{cite web |title=Lake Nipissing |url=http://www.ontarioplaques.com/Plaques/Plaque_Parry07.html |website=Ontario's Historical Plaques |publisher=Alan L Brown |access-date=15 December 2018}}</ref>

== History ==
{{see also|Ottawa River timber trade}}
As it does to this day, the river played a vital role in life of the [[Algonquin people]], who lived throughout its watershed at contact.  The river is called ''Kichisìpi'', meaning "Great River" in [[Algonquin language|Anicinàbemowin]], the Algonquin language. The Algonquin define themselves in terms of their position on the river, referring to themselves as the Omàmiwinini, 'down-river people'.  Although a majority of the Algonquin First Nation lives in Quebec, the entire Ottawa Valley is Algonquin traditional territory.  Present settlement is a result of adaptations made as a result of settler pressures.<ref name="Algonquin Ontario Land Claim">{{cite web |url=http://www.aboriginalaffairs.gov.on.ca/english/negotiate/algonquin/algonquin.asp |title=Algonquin Land Claim with Ontario |publisher=Ontario Ministry of Aboriginal Affairs |access-date=2009-06-30 |archive-date=2013-06-06 |archive-url=https://web.archive.org/web/20130606064851/http://www.aboriginalaffairs.gov.on.ca/english/negotiate/algonquin/algonquin.asp |url-status=dead }}</ref>

[[File:ottawarivermattawa.jpg|thumb|right|A railway bridge over the Ottawa River in [[Mattawa, Ontario]].]]Some early European explorers, possibly considering the Ottawa River to be more significant than the Upper St. Lawrence River, applied the name ''River Canada'' to the Ottawa River and the St. Lawrence River below the confluence at Montreal. As the extent of the [[Great Lakes]] became clear and the river began to be regarded as a tributary, it was variously known as the ''Grand River'', "Great River" or ''Grand River of the Algonquins'' before the present name was settled upon. This name change resulted from the [[Ottawa (tribe)|Ottawa people]]s' control of the river circa 1685. However, only one band of Ottawa, the Kinouncherpirini or Keinouch, ever inhabited the [[Ottawa Valley]].

In 1615, [[Samuel de Champlain]] and [[Étienne Brûlé]], assisted by Algonquin guides, were the first Europeans to travel up the Ottawa River and follow the water route west along the Mattawa and French Rivers to the Great Lakes. See [[Canadian Canoe Routes (early)]]. For the following two centuries, this route was used by [[France|French]] [[fur trade]]rs, [[voyageurs]] and [[coureurs des bois]] to Canada's interior. The river posed serious hazards to these travellers. The section near [[Head, Clara and Maria, Ontario|Deux Rivières]] used to have spectacular and wild rapids, namely the ''Rapide de la Veillée'', the ''Trou'', the ''Rapide des Deux Rivières'', and the ''Rapide de la Roche Capitaine''. (These rapids are now submerged under the reservoir of Holden Lake.) In 1800, explorer Daniel Harmon reported 14 crosses marking the deaths of voyageurs who had drowned in the dangerous waters along this section of the Ottawa.<ref name="OHF">Ontario Heritage Foundation, Ministry of Culture and Communications</ref>

The main trading posts along the river were: [[The Fur Trade at Lachine National Historic Site|Lachine]], [[Fort-Coulonge, Quebec|Fort Coulonge]], [[Sheenboro, Quebec|Lac des Allumettes]], [[Mattawa, Ontario|Mattawa House]], where west-bound canoes left the river and [[Fort Témiscamingue]]. From Lake Timiskaming a portage led north to the [[Abitibi River]] and James Bay.

In the early 19th century, the Ottawa River and its tributaries were used to gain access to large virgin forests of [[Eastern White Pine|white pine]]. A booming [[Lumber industry on the Ottawa River|trade in timber]] developed, and large [[timber rafting|rafts of logs]] were floated down the river. A scattering of small subsistence farming communities developed along the shores of the river to provide manpower for the [[lumber camp]]s in winter. In 1832, following the [[War of 1812]], the Ottawa River gained strategic importance when the [[Carillon Canal]] was completed. Together with the [[Rideau Canal]], the Carillon Canal was constructed to provide an alternate military supply route to [[Kingston, Ontario|Kingston]] and [[Lake Ontario]], bypassing the route along the [[Saint Lawrence River]].<ref name="PC-carillon">{{cite web |url=http://www.pc.gc.ca/lhn-nhs/qc/canalcarillon/natcul/natcul2_E.asp |title=Carillon Canal National Historic Site of Canada, Cultural Heritage |publisher=Parks Canada |access-date=2009-02-09 |url-status=dead |archive-url=https://web.archive.org/web/20070506161717/http://www.pc.gc.ca/lhn-nhs/qc/canalcarillon/natcul/natcul2_e.asp |archive-date=2007-05-06 }}</ref>

==Power generation==
A pulp and paper mill (at [[Témiscaming]]) and several [[hydroelectricity|hydroelectric]] dams have been constructed on the river. In 1950, the dam at [[Rapides-des-Joachims, Quebec|Rapides-des-Joachims]] was built, forming Holden Lake behind it and thereby submerging the rapids and portages at Deux Rivières.<ref name="OHF"/> These hydro dams have had negative effects upon shoreline and wetland ecosystems,<ref>Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK.497 p.</ref> and are thought to also be responsible for the near extermination of [[American eel]]s, which were once an abundant species in the river, but which are now uncommon.<ref>{{cite web |title=COSEWIC Assessment and Status Report on the American Eel in Canada |url=http://publications.gc.ca/collections/Collection/CW69-14-458-2006E.pdf |pages=45–46|publisher=Committee on the Status of Endangered Wildlife in Canada |access-date=December 15, 2018}}</ref> As an economic route, its importance was eclipsed by railroad and highways in the 20th century. It is no longer used for log driving, however, it is still extensively used for recreational boating. Some 20,000 pleasure boaters visit the Carillon Canal annually.<ref name="PC-carillon"/>

Today, [[Outaouais Herald Emeritus]] at the [[Canadian Heraldic Authority]] is named after the river.

=== Hydroelectric installations ===

Hydroelectric installations on the Upper Ottawa (in downstream order):
{| class="wikitable"
|- style="background:#abcdef;" 
| style="width:26%;"| Installation
| style="width:16%;"| Type
| style="width:11%;"| Generating cap.
| style="width:11%;"| Year built
| style="width:16%;"| Name of reservoir
| style="width:20%;"| Operator
|-
| Bourque Dam
| Dam || n/a || 1949 || [[Dozois Reservoir]] || [[Hydro-Québec]]
|-
| Rapide-7
| Generating station || 48 MW || 1941 / 1949 || Decelles Lake || Hydro-Québec
|-
| Rapide-2
| [[Run-of-the-river hydroelectricity|Run of river]] g.s. || 48 MW || 1954 || n/a || Hydro-Québec
|-
| Rapides-des-Quinze
| Run of river g.s. || 95 MW || 1923 || n/a || Hydro-Québec
|-
| Rapides-des-Îles
| Run of river g.s. || 147 MW || 1966 || n/a || Hydro-Québec
|-
| Première-Chute
| Run of river g.s. || 130 MW || 1968 || n/a || Hydro-Québec
|}

Lower Ottawa (in downstream order):
{| class="wikitable"
|- style="background:#abcdef;" 
| style="width:26%;"| Installation
| style="width:16%;"| Type
| style="width:11%;"| Generating cap.
| style="width:11%;"| Year built
| style="width:16%;"| Name of reservoir
| style="width:20%;"| Operator
|-
| Otto Holden
| Run of river g.s. || 243 MW || 1952 || n/a || [[Ontario Power Generation]]
|-
| Des Joachims
| Run of river g.s. || 429 MW || 1950 || Holden Lake || Ontario Power Generation
|-
| Bryson
| Run of river g.s. || 61 MW || 1925 || n/a || Hydro-Québec
|-
| Chenaux
| Run of river g.s. || 144 MW || 1950 || n/a || Ontario Power Generation
|-
| [[Chats Falls Generating Station|Chute-des-Chats (Chats Falls)]]
| Run of river g.s. || 185 MW || 1931 || Lac des Chats || Hydro-Québec and OPG *
|-
| [[Hull-2]]
| Run of river g.s. || 27 MW || 1920 || n/a || Hydro-Québec
|-
| [[Carillon Generating Station|Carillon]]
| Run of river g.s. || 752 MW || 1962 || n/a || Hydro-Québec
|}
<nowiki>*</nowiki> Ontario Power Generation operates generators 2, 3, 4, and 5 with a capacity of 96 MW; and Hydro-Québec operates generators 6, 7, 8, and 9 with a capacity of 89 MW.

{{wide image|Ottawario.jpg|1000px|align-cap=center|Ottawa River overlooking  [[Parliament Hill]] to the left and the [[Canadian Museum of History]] to the right}}

==Protected areas==
Numerous non-contiguous areas of the Ottawa River and its shores are protected in a variety of provincial parks, conservation areas, and municipal parks.<ref name="CHRS">{{cite web |title=A Background Study for Nomination of the Ottawa River Under the Canadian Heritage Rivers System |url=https://www.ottawariver.org/pdf/20-ch3-8.pdf |website=www.ottawariver.org |publisher=Ottawa River Heritage Designation Committee |access-date=19 April 2024 |pages=183-189 |date=2005}}</ref>

In Quebec, there are 3 national parks directly along the Ottawa River ([[Oka National Park]], [[Plaisance National Park]], and [[Opémican National Park]]), as well as one major nature reserve through which the river runs ([[La Vérendrye Wildlife Reserve]]). Several ZECs ([[zone d'exploitation contrôlée]]) also line the Ottawa River.<ref name="CHRS"/>

Ontario has 7 provincial parks along the banks of the Ottawa River: [[Voyageur Provincial Park]], [[Fitzroy Provincial Park]], Ottawa River Provincial Park, [[Westmeath Provincial Park]], [[Petawawa Terrace Provincial Park]], [[Driftwood Provincial Park]], and [[Alexander Lake Forest Provincial Park]]).<ref name="CHRS"/>

===Ottawa River Provincial Park===
{{Infobox protected area
|name            = Ottawa River Provincial Park
|alt_name        = 
|iucn_category   = ii
|iucn_ref        = 
|location        = [[Renfrew County]], Ontario, Canada
|coordinates     = {{Coord|45|42|55|N|76|43|12|W|region:CA-ON_type:landmark|display=inline}}
|coords_ref      = <ref name="FEVLH"/>
|length          = 
|length_km       = 
|width           = 
|width_km        = 
|area_ha         = 125.05
|area_ref        = <ref name="OP"/>
|elevation       = 
|elevation_avg   = 
|elevation_min   = 
|elevation_max   = 
|designation     = Waterway
|established     = 1989
|visitation_num  = 
|visitation_year = 
|visitation_ref  = 
|governing_body  = [[Ontario Parks]]
|url             = https://www.ontarioparks.ca/park/ottawariver
|child           = 
|embedded        = 
|embedded1       = 
|embedded2       = 
}}

The Ottawa River Provincial Park is in the Township of [[Whitewater Region]], Ontario, protecting a series of pristine islands and a small undeveloped section of shoreline along the Ontario side of the Ottawa River.<ref name="FEVLH">{{Cite cgndb |FEVLH |Ottawa River Provincial Park |access-date=20 April 2024}}</ref> This section of the Ottawa River is known for its [[whitewater]], and is used by a number of commercial rafting companies and many recreational kayakers and canoeists.<ref name="OP">{{cite web |title=Ottawa River Provincial Park |url=https://www.ontarioparks.ca/park/ottawariver |website=www.ontarioparks.com |publisher=Ontario Parks |access-date=20 April 2024}}</ref><ref name="mgmt">{{cite web |title=Ottawa River Provincial Park Management Statement |url=https://www.ontario.ca/page/ottawa-river-provincial-park-management-statement |publisher=Ontario Ministry of Natural Resources |access-date=20 April 2024 |language=en |date=February 1998 }}</ref>

The park is a non-operating park, meaning that there are no services and facilities for visitors. The park can be used for backcountry camping, whitewater canoeing, swimming, hunting, and fishing.<ref name="OP"/>

Some of the islands included in the park are Big, Butternut, Cedar, Hazelton, and Lorne Islands, in addition to many unnamed islands. They consists of marble bedrock or low-lying alluvial sands and silts. A total of sixteen regionally significant plant species, such as little bluestem (''[[Andropogon scoparius]]''), cordgrass (''[[Spartina pectinata]]'') and Indiangrass (''[[Sorghastrum nutans]]'') have been found in the park, as well as the nationally significant lake cress (''[[Rorippa aquatica]]'').<ref name="mgmt"/>

==See also==
{{Portal|Ontario}}
{{Colbegin}}
*[[Lac Deschênes]]
*[[List of Ontario rivers]]
*[[List of crossings of the Ottawa River]]
*[[List of islands of Ontario#Ottawa River]]
*[[List of longest rivers of Canada]]
*[[Southern Ontario]]
*[[Eastern Ontario]]
*[[List of Quebec rivers]]
*[[Rivière des Mille Îles]]
*[[Rivière des Prairies]]
{{colend}}

==References==
{{reflist|colwidth=30em}}

==External links==
{{Commons category}}
* [https://web.archive.org/web/20090331043113/http://www.ogwa-hydrog.ca/ Ottawa-Gatineau Watershed Atlas (OGWA)]
* [http://www.ottawariver.ca/ Ottawa River Regulation Planning Board]
* [http://www.ottawariverkeeper.ca/ Ottawa Riverkeeper]
* [https://web.archive.org/web/20080228052929/http://www.greatcanadianrivers.com/rivers/ottawa/culture-home.html The Ottawa River]
* [http://www.tolatsga.org/alg.html Algonkin History] {{Webarchive|url=https://web.archive.org/web/20050107094124/http://www.tolatsga.org/alg.html |date=2005-01-07 }}
{{Ottawa}}

{{Authority control}}

[[Category:Ottawa River| ]]
[[Category:Rivers of Ottawa]]
[[Category:Landforms of Gatineau]]
[[Category:Rivers of Montérégie]]
[[Category:Rivers of Outaouais]]
[[Category:Borders of Quebec]]
[[Category:Borders of Ontario]]