Illinois Caverns state natural area, featuring the Mommoth Cove of Illinois,  started its commercial operations in March 1901 and was sold to the State of Illinois in 1985 under Armin Krueger's management.
Illinois Caverns state natural area, featuring the Mommoth Cove of Illinois,  started its commercial operations in March 1901 and was sold to the State of Illinois in 1985 under Armin Krueger's management.