It flows 100 kilometres (62 mi) from Montreal Lake to Lac la Ronge and is part of the Churchill River and Hudson Bay drainage basins.

Along its course, Montreal River runs through boreal forests, muskeg, and glacier formed valleys.

[2] Montreal River begins at Montreal Lake 5 kilometres (3.1 mi) north of the community of Molanosa and 4 kilometres (2.5 mi) west of Highway 969.

It is a small roadside pull-out campground off of Highway 2 with six campsites.

[6] Fish species commonly found in the river include walleye, sauger, yellow perch, northern pike, lake trout, lake whitefish, cisco, burbot, white sucker, and longnose sucker.