🌿 Ravine walk · Humber River
The Humber Marshes walk — Humber Bay to Old Mill
Three kilometres along the Humber River, from a Lake Ontario salt marsh to the pre-industrial mill ruins at Old Mill — the river that flooded catastrophically in 1954 and, in doing so, gave Toronto its ravine system
The Humber is the widest and most historically important of Toronto's rivers. Indigenous peoples used it for millennia as the southern end of the Toronto Carrying-Place trail — the portage route between Lake Ontario and Georgian Bay. Its mouth is a rare salt-influenced marsh ecosystem right inside the city. And in October 1954 it flooded, killing dozens of people on Raymore Drive and triggering the policy response that made Toronto's ravine system possible. This walk covers the lower three kilometres of the river — the marsh at the mouth, the flood-plain forest, and the ruins of an 18th-century grist mill.
The stops
Start — Humber Bay Arch Bridge
The distinctive white arch bridge at the mouth of the Humber. The structure is modern (1994), but the salt marsh it crosses is ancient — one of the few remaining stretches of lake-influenced marsh habitat in the city. Great blue herons and cormorants are common. Kingfishers in the right season.
Humber Marshes
Head north on the east-bank Humber Recreational Trail. The salt-influenced lower marsh gives way quickly to fresh-water wetland and then to typical flood-plain forest — silver maple, black willow, cottonwood, some stands of eastern white cedar. The trees along the water are short-lived but fast-growing; turnover here is measured in decades, not centuries.
South Humber Park
The mid-point of the walk. A wide grassy oxbow where the Humber bends east; one of the best free picnic spots within TTC distance of downtown. The mature silver maples along the riverbank here are among the few tall trees in this stretch — most of the flood-plain forest is short-lived pioneer species (cottonwood, black willow) because the ground gets wet every few years.
The Hurricane Hazel memorial is on Raymore Drive, about 4 km further upstream at Lawrence and Weston — not on this walk. If you want to see where the disaster happened, that's a separate longer trip.
End — Old Mill
The King's Mill, built in 1793, was one of the first European industrial sites in what became Toronto. You are now standing in and around the stone ruins of the 1848 successor mill, with the subway station 300 metres up the hill. The ruined walls, the river's sharp bend here, and the old footbridge make this one of the more cinematic corners of the city.
Practical notes
Timing: excellent year-round. Best October for foliage along the silver maples and cottonwoods; best April–May for returning waterfowl in the marsh.
TTC: start at Mimico GO (5 min walk to Humber Bay) or take the 66 or 80 bus from Old Mill station. End at Old Mill (Line 2).
Terrain: paved multi-use trail the entire way, mostly flat with a gentle climb near Old Mill. Stroller- and wheelchair-accessible.
See also the other ravine walks: Don Valley — Brick Works to Chorley Park and Warden Woods → Taylor Creek Park.