The Grand Hogback is a 70-mile long, curving, spine-like ridge in Western Colorado that extends from near McClure Pass in Pitkin County through Garfield County and then to near Meeker in Rio Blanco County. The hogback is significant because it marks part of the boundary between the Colorado Plateau to the west and the Southern Rocky Mountains to t…The Grand Hogback is a 70-mile long, curving, spine-like ridge in Western Colorado that extends from near McClure Pass in Pitkin County through Garfield County and then to near Meeker in Rio Blanco County. The hogback is significant because it marks part of the boundary between the Colorado Plateau to the west and the Southern Rocky Mountains to the east.