Castle Mountain (Blackfoot: Miistukskoowa) is a mountain located within Banff National Park in the Canadian Rockies, approximately halfway between Banff and Lake Louise. It is the easternmost mountain of the Main Ranges in the Bow Valley and sits astride the Castle Mountain Fault which has thrust older sedimentary and metamorphic rocks forming the upper part of the mountain over the younger rocks forming its base. The mountain's castellated, or castle-like, appearance is a result of erosive processes acting at different rates on the peak's alternating layers of softer shale and harder limestone, dolomite and quartzite.