Twelve coal seams occur in the Jurassic-Cretaceous Mist Mountain Formation (Kootenay Group) interbedded with sandstone, shale and siltstone. Total thickness of the coal-bearing strata ranges up to 610 metres, containing approximately 45.7 metres of coal. The ascending order of seams is 10, 9, 8, 7, 6, 5, 3, A, B, C Lower, C Upper and D. The A, B, C and D seams vary from medium to high volatile bituminous to high volatile rank in the upper seams. Seams A, B, C and D are the more recent mining targets in the Natal Ridge area.

The strata strikes generally north to northwest and dips west, thus representing the east limb of the Sparwood syncline. There are a number of thrust faults (generally north-northwest trending, west dipping) and fewer, almost vertical normal faults.

Recent emphasis has been on strip mining. The A seam on Natal Ridge is close to the old Erickson strip mine. The No. 7 seam strip mine, the No. 3 seam strip mine and the C seam strip mine are the mines in the area. The No. 7 seam mine is 3.2 kilometres southwest of Michel and exploits the 9.4 metre thick coal seam. The seam contains a 1.8 metre parting and dips southwest at 15-20 degrees. The No. 3 seam at the No. 3 seam strip mine, which is 4 kilometres northwest of Michel, is 9.1 metres thick and contains two soil bands totalling 3.7 to 4.6 metres in thickness. The C seam strip mine operated for a small number of years on the Upper and Lower C seams. The coal has high moisture content.