The canal in Cadillac connects Lake Cadillac and Lake Mitchell. It historically was referred to as the Clam Lake Canal, Lake Cadillac was formerly called Clam Lake. The river that empties the lake is still called Clam River. The canal was constructed in 1873 and has been widened several times since then. The canal is famous for freezing over before the adjoining lakes and then thawing as soon as the lakes freeze, remaining unfrozen the rest of the winter.