This gateway to Quetico wilderness begins on a boardwalk that winds through forest-covered lowland thick with mosses, Labrador tea, horsetail, twinflower, bunchberry, pyrola, black spruce and tamarack.

The boardwalk gives way to a footpath that meanders through a mosaic of forest habitats. (Caution: Terrain is slippery when wet.) Quetico is a protected, pristine wilderness retreat of international acclaim west of Lake Superior on the Canada-U.S. border. The park’s tangled network of lakes once formed water routes travelled by Ojibway and fur traders.

Now it is primarily the destination of experienced canoeists seeking solitude and rare glimpses of wildlife by cascading waterfalls, glassy...