The Subarctic Subregion occurs on the tops of the Birch Mountains, the Caribou Mountains, and the Cameron Hills. These hill systems are
erosional remnants that rise above the surrounding plain as flat-topped hills with
escarpments that are dissected by numerous small streams.
Surficial deposits are primarily either till or organic peat. The latter predominates in the Subregion and contains discontinuous
permafrost. Palsas and peat plateaus occur in these
peatland areas and are landforms characteristic of subarctic conditions.
Morainal and organic deposits occur on the plateaus, and morainal blankets occur over rolling residuum on the flanks of the hills.