Coal seams occur in the Telkwa coal measures interbedded with shale, carbonaceous units and sandstone of the Lower Cretaceous Skeena Group. On the south side of Glacier Gulch approximately 20 coal seams occur throughout a 183 metre thick section. The majority of the seams range from 0.2 metres to 0.3 metres thick, however two seams up to 1.2 metres thick, and two ranging from 0.5 to 0.6 metres thick also occur. On the north side of Glacier Gulch four thin (less than 0.6 metres) coal seams are present. Coal has been mined from a number of adits and analyses of various adit samples yield ash, volatile matter, fixed carbon, sulphur and BTU per pound values ranging from 9.5 to 28.1 per cent, 3.1 to 7.1 per cent, 69.8 to 51.4 per cent, 0.1 per cent and 9,100 to 10,200 respectively (1940). A small tonnage of coal was mined from the Lake Kathlyn Coal Mine from a series of adits.

Beds strike northwest and dip northeast 55 to 70 degrees. The coal is sheared in places and locally contains numerous slickensides. A number of faults are also present in the area.