The lower 24 km (15 mi) and upper reaches of the river consist of sandy, meandering portions, with numerous loops and oxbow lakes.

The park, located about 160 kilometres (99 mi) north of Thunder Bay, is notable for its multi-day canoe camping opportunities.

[8] Furthermore, the Ottertooth Conservation Reserve abuts the Gull River Provincial Park on both sides southwest of Detour Lake.

[9] The landscape in Gull River Provincial Park is characterized by boreal forests with deciduous-dominated mixedwood and jack pine/black spruce mixed stands, as well as wetlands, marshes, and fens.

[4][7] Mammals found in the park include black bear, fisher, lynx, mink, moose, pine marten, red fox, snowshoe hare, and timber wolf.