Indigo Tunnel
Indigo Tunnel is an abandoned railroad tunnel in Allegany County, Maryland, located about east of Little Orleans. Built by the Western Maryland Railway in 1904, Indigo was the company's longest tunnel. It was part of a major WM project to extend its rail system from Hagerstown west to Cumberland. This difficult route followed the Potomac River valley and involved construction of four additional tunnels and 23 bridges. The new rail line opened for traffic in 1906. Trains ran through the tunnel until the rail line was abandoned by the newly formed Chessie System in 1975, in favor of the parallel Baltimore and Ohio railroad line on the opposite side of the Potomac River.
The tunnel was acquired by the National Park Service in 1980 and became part of Chesapeake and Ohio Canal National Historical Park. The Park Service has identified bat colonies living in the tunnel and has closed the tunnel to the public in order to protect the colonies.
