The crew of the Medusa Challenger checks clearances as they navigate the C&NW KK River bridge in Milwaukee, WI in December of 1994. The C&NW bridge was once double tracked and carried numerous passenger trains daily (including the famed "400") on their way to the Milwaukee depot. Today, and at the time of this photo, the bridge is single track and only sees one local train a day. It is operated from the river shoreline. The Challenger was built in 1906 and still survives, although it has been cut down to a barge