Side Trails » Crystal Lake Cave
In 1868 lead miners drilled 40 feet into the ground to find traces of a rich lead vein. They found a natural geological wonder.
Source: Crystal Lake Cave, Dubuque
Iowa Pathways: Iowa History Resources for Students and Teachers
Home ~ My Path ~ Artifacts ~ Timeline ~ Quest ~ Teacher Resources ~ Project Information ~ SponsorsIowa Pathways © 2005 - 2017 Iowa Public Television