Grotto Arch, Pierce County, Wisconsin
Photo by Andrew VonBank
NABSQNO 15T-519730-4964285. Grotto Arch is a buttress natural arch eroded through Prairie du Chien dolomite. It is located in Kinnickinnic State Park, Pierce County, Wisconsin, about six miles northeast of Prescott, or 18 miles southeast of St. Paul, Minnesota. Access requires a short, but steep and unmarked bushwack off of a park trail. The arch has a span of about 10 feet and a height of about 10 feet.