The Sawtooth is recognized in the south-central Alberta Plains and in Montana north and west of the Sweetgrass Arch. Thicknesses are highly variable, as the Sawtooth overlies a high-relief surface sculpted in Mississippian carbonates by pre-Jurassic erosion. At the type locality the Sawtooth is 5 m (16 ft) thick; it thins eastward and pinches out over the Sweetgrass Arch, except in areas of southern Alberta, where a thin sandstone remains. The northern subcrop edge in Ranges. 11-15W4 in southern Alberta is deeply dissected by pre-Cretaceous erosion.