[4] A sequence of interbedded, highly variable-proportioned grey mudstone to sandstone layers makes up the bottom portion of the underlying Gladstone Formation.

[4] The Beaver Mines and Ma Butte formations in the upper part of the group also include minor beds of bentonite and tuff.

[1] In the type area, tuffaceous mudstones are widespread in the top portion of the formation, but they vanish to the northwest along the foothills.

[4] In the Smoky River region, the uppermost part of the formation, the proportion of the section with a conspicuously greenish tint is restricted to a subtle shade of greenish-grey as it declines northward.

[1] The name Blairmore Group is applicable in the foothills and mountains of southwestern Alberta and southeastern British Columbia, from the Canada–United States border northward to the Clearwater River.

[4] The easternmost foothills have reported thicknesses of roughly 300 m (980 ft), indicating a clear west to east thinning.