The river begins in the Porcupine Hills of the Manitoba Escarpment at Armit Lake and flows in a northerly direction closely following the Manitoba / Saskatchewan border and into Red Deer Lake along the course of the Red Deer River.

North from Muskeg Lake, the river flows through the 264-hectare (650-acre) Armit Meadows Ecological Reserve[4][5] and then into Armit River Canyon,[6] which takes it out of the Porcupine Hills and back into Saskatchewan.

Armit River carries on to the north-east and into a large marshy estuary at Red Deer Lake.

It has a small campground, hiking trails, and access to the river for fishing.

[10] Armit River (and its tributaries) have a naturalised population of brook trout.