Under the canopy, the Mast Trail follows the creek through thicket and forest. You hear the water before the trees break on a wet meadow and a farm field, the river still in earshot. Then you are under leaves again, which is how this valley works. You stay in that corridor the whole way, a walk that is still inside the city.
The Mast Trail takes a full afternoon in Rouge National Urban Park, forest to farmland to wetland and back to the river, and you are still at the van before dark.
Glen Rouge is the old overnight at the edge of that valley. Parks Canada lists it as a day-use area. TRCA states the campground remains closed, and Ajax has no public campground of its own. You can still start the Mast Trail from that edge, then you move the van for the night.
Rouge Beach and Zoo Road are off the map for now. As of September 2026, Parks Canada has Rouge Beach and the Waterfront Trail there closed for construction into 2027, and the Zoo Road day-use area closed for a new visitor centre into 2027. The Mast Trail and the other valley walks still carry the day.
The Toronto Zoo keeps a separate entrance and is open. It shares the Rouge valley with the park, so a zoo afternoon is a straightforward add-on after the walk.
Sleep at Darlington Provincial Park on Lake Ontario, the public overnight Oshawa already covers. If you need more sleeping space than a van, look at Ajax RV rentals. For Algonquin, start from Toronto.
Duffins Creek at Greenwood Conservation Area
Greenwood Conservation Area is Duffins Creek in Ajax, the same valley continuing into Pickering with trails staying by the creek through forest. TRCA describes a cold-water stream in a mostly rural, forested watershed and calls Duffins Creek "one of the healthiest streams in the Greater Toronto Area". There is no overnight at Greenwood, so you walk the creek and drive on.
Lynde Shores Conservation Area in Whitby
Cranberry Marsh and Lynde Creek Marsh open in front of the viewing platforms at Lynde Shores Conservation Area in Whitby. Waterfowl and shorebirds use both marshes as a stopover. You watch from the platforms or keep moving on the accessible Waterfront Trail. CLOCA allows dogs on leash on that Waterfront Trail only and opens the canoe and kayak launch mid-July to mid-September.