Petawawa River

Petawawa River
The dangerous Crooked Chute in Algonquin Provincial Park
Name origin: From the Algonquian for "where one hears a noise like this"
Country	Canada
Ontario	Ontario
Regions	Eastern Ontario, Northeastern Ontario
Districts	Renfrew County, Nipissing District
Part of	Saint Lawrence River drainage basin
Tributaries
- left	North River, Nipissing River, Tim River
- right	Barron River, Crow River, Little Madawaska River
Source	Ralph Bice Lake
- location	Geographic township of Butt, Unorganized South Part, Nipissing District
- elevation	443 m (1,453 ft)
- coordinates	45°40′49″N 78°57′02″W / 45.68028°N 78.95056°W / 45.68028; -78.95056
Mouth	Ottawa River
- location	Petawawa, Renfrew County
- elevation	110 m (361 ft)
- coordinates	45°54′38″N 77°15′31″W / 45.91056°N 77.25861°W / 45.91056; -77.25861Coordinates: 45°54′38″N 77°15′31″W / 45.91056°N 77.25861°W / 45.91056; -77.25861
Length	187 km (116 mi)
Basin	4,200 km2 (1,622 sq mi)
Discharge
- average	45 m3/s (1,589 cu ft/s)
Location of the mouth of the Petawawa River in Ontario

The Petawawa River is a river in the Saint Lawrence River drainage basin in Nipissing District and Renfrew County in eastern and northeastern Ontario, Canada. The river flows from Algonquin Provincial Park to the Ottawa River at the town of Petawawa, and is only one of two major tributaries of the Ottawa River to flow completely free (the other being the Dumoine River). The river's name comes from the Algonquian for "where one hears a noise like this", which refers to its many rapids.

The river starts at Ralph Bice Lake (formerly Butt Lake) in northern Algonquin Provincial Park in the geographic township of Butt in the Unorganized South Part of Nipissing District. It flows south to Daisy Lake then east to Big Trout Lake. The river heads north out the lake over Big Trout Lake Dam, takes in the left tributary Tim River, flows over the Portal Rapids, Cedar Rapids, Snowshoe Rapids, Catfish Rapids, and Stacks Rapids to reach Cedar Lake, the location of the community of Brent, where it takes in the left tributary Nipissing River. The river exits the lake over a dam, heads through the Devil's Chute, reaches Radiant Lake, where it takes in the left tributary North River and right tributary Little Madawaska River, and passes through the Squirrel Rapids, Big Sawyer Rapids, Battery Rapids Cascade Rapids and White Horse Rapids, and takes in the right tributary Crow River. The river then continues through a series of rapids including the Devil's Cellar Rapids, passes the Algonquin Radio Observatory, and reaches Lake Travers. The Petawawa River enters a canyon and passes through numerous rapids including the Big Thompson Rapids, Little Thompson Rapids, Grillade Rapids, Crooked Chute, Rollway Rapids, The Natch, Schooner Rapids, Five Mile Rapids to arrive at Whitson Lake adjacent to the Petawawa Hills. It leaves Algonquin Provincial Park and enters the municipality of Laurentian Hills in Renfrew County, continues southeast past CFB Petawawa, passes through the Crooked Rapids, Race Horse Rapids, White Horse Rapids and Halfmile Rapids, and reaches Lac du Bois Dur, where it takes in the right tributary Barron River. The river enters the town of Petawawa, heads under Ontario Highway 17, through the Big Eddy Rapids, under the Canadian Pacific Railway main line, and empties into Black Bay on the Ottawa River.