An unnamed buttress natural arch, Mineral County, Colorado
Photo by Jay Wilbur
NABSQNO 13S-315230-4181150. This unnamed buttress natural arch has eroded through volcanic tuff. It is located on the east side of Colorado Highway 149 just north of its intersection with Fern Creek Road, about 8 miles northwest of Spar City in Mineral County, Colorado. The arch has a span of 4 feet and a height of 12 feet.