Opeongo River
Opeongo River near the confluence with the Aylen River
Location of the mouth of the Opeongo River in southern Ontario
Location
Country	Canada
Ontario	Ontario
Region	Northeastern Ontario
District	Nipissing
Physical characteristics
Source	Opeongo Lake
• location	Preston Township, Unorganized South Nipissing District; in Algonquin Provincial Park
• coordinates	45°41′55″N 78°16′28″W / 45.69861°N 78.27444°W / 45.69861; -78.27444
• elevation	403 m (1,322 ft)
Mouth	Madawaska River
• location	East of Madawaska village, South Algonquin Township
• coordinates	45°30′22″N 77°56′45″W / 45.50611°N 77.94583°W / 45.50611; -77.94583
• elevation	311 m (1,020 ft)
Basin features
River system	Saint Lawrence River drainage basin

The Opeongo River is a river in the Saint Lawrence River drainage basin in Nipissing District in northeastern Ontario, Canada.^[1][2] The river is entirely within Algonquin Provincial Park and Opeongo River Provincial Park, except for a small portion around Victoria Lake, and is a left tributary of the Madawaska River.

Course

The river begins in Algonquin Provincial Park at the outflow from Annie Bay on the East Arm of Opeongo Lake in geographic Preston Township, in the Unorganized South Part of Nipissing District, controlled by the Opeongo Lake Dam and flows southeast to Booth Lake. It exits the lake east controlled by the Booth Lake Dam, enters geographic Clancy Township, exits Algonquin Provincial Park into Opeongo River Provincial Park^[3] and reaches Victoria Lake. The river leaves the lake at the northeast over a dam and continues southeast, passes from Unorganized South Nipissing District into the geographic Dickens Township in the municipality of South Algonquin, passes through a series of rapids, takes in the left tributary Aylen River, turns southwest, and empties into Bark Lake on the Madawaska River, at the Ontario Highway 60 bridge and east of the community of Madawaska. The Madawaska River flows via the Ottawa River to the Saint Lawrence River.

Recreation

The river is used for recreational canoeing and kayaking.

Tributaries

• Aylen River (left)
• Victoria Lake
  • McNevin Creek (right)
• Shall Lake
  • Oram Creek (right)
  • Shall Creek (left)
• Crotch Lake
  • Shirley Creek (left)
  • Robin Creek (left)
• Bridle Creek (left)
• Booth Lake
  • Rumley Creek (right)
  • Cob Creek (right)
  • McCarthy Creek (right)
  • Chipmunk Creek (left)
• Tip Up Creek (left)