The Petawawa River drains the central interior of Algonquin Park before cutting southeast through the Ottawa Valley. Its 200 km run from Cedar Lake to the Ottawa River at Petawawa includes everything from flatwater lake crossings to sustained Class III rapids — making it one of the more technically varied multi-day trips in Ontario.
This profile covers the section from Traverse Lake (accessible from Highway 60 at km 103) to the take-out near McManus Road, approximately 160 km by water. The upper lake section is slower and more suitable for canoeists of mixed experience; the lower 60 km requires confident water-reading ability and should not be underestimated at high spring flows.
Access points
The most used put-in is at the Traverse Lake portage off Highway 60 inside Algonquin Park. A $10 per person per night interior permit is required for any camping within park boundaries. The permit system is managed through the Ontario Parks online reservation system and fills quickly for the May and June windows.
The take-out at McManus Road (County Road 28) requires leaving a vehicle — most parties arrange a two-car shuttle from Petawawa town or use one of the shuttle operators based in Whitney. The nearest shuttle contact as of 2025 is Algonquin Outfitters in Oxtongue Lake (+1 705-635-2243).
Gradient and river character
The upper section from Traverse Lake to Lake Travers drops at roughly 1.5 m/km — very gentle, with most of the elevation carried through a series of long flatwater passages between lakes. The character changes sharply below Lake Travers. The Petawawa narrows and accelerates through the Natch — a canyon section with back-to-back Class II and III drops over about 8 km.
Portage summary
Eight portages are documented on this route. Conditions below are as reported in the 2024 season. Trail states can shift significantly after winter blowdowns.
Portage 1 — Poplar Rapids (P1)
330 m, flat trail, well maintained. Start river-left above the visible horizon line. Ends at a gravel beach with good landing for loaded canoes.
Portage 2 — Cedar Falls (P2)
180 m, avoids an unrunnable 4 m ledge. Trail is rooted in the middle section — one trip carries are easier on dry days. There is no safe line through the falls at any recorded flow.
Portage 3 — The Natch upper (P3)
At high water (above 120 m³/s), a 750 m portage on river-left bypasses the entire upper canyon. At moderate flows the first drop can be run and a shorter 220 m trail on river-right bypasses the technical lower section. Scout from the right bank above the drop before committing.
Portages 4–8
The remaining five portages are shorter (40–150 m each), mostly avoidable at moderate flows, and carry less consequence. At low-water periods in late summer several rapids become scrapy Class I bony runs that require wading rather than paddling to protect hull integrity.
Camping
Inside Algonquin, camping is restricted to designated interior campsites marked on the Ontario Parks permit map issued at purchase. Outside the park boundary the river passes through Crown land where dispersed camping is permitted. There are no developed facilities south of the park boundary — pack out all waste.
Seasonal window
The Petawawa corridor runs best from late April through mid-June when snowmelt keeps flows above 30 m³/s. July and August are possible but some sections become shallow and rocky. Ice generally clears from the lake crossings by mid-April, though this varies by year.
"The Natch at 70 m³/s gives you good water to read your lines, but the pace is unrelenting. Don't run it without solid bracing and reliable rolls if you're in a kayak — the recovery pools are short." — Trip report, June 2024
Safety notes
The Petawawa is a remote river. The lower canyon is several kilometres from any road. Cell service is absent through most of the park interior. Carry a satellite communicator. Parks Canada recommends filing a float plan with a contact person before any multi-day interior trip. The nearest hospital is in Pembroke, approximately 60 km from the take-out at McManus Road.
Strainers are a documented hazard on the sections below the park boundary where the river passes through agricultural land and occasional logjams form after ice-out. Scout any blind corners in spring at high water.