Indigo Tunnel was built in 1904. The drilling equipment was barged in on the adjacent C&O Canal. The tunnel was drilled at a length of 4,350 ft. just short of one mile. The gray slate from the tunnel was hauled out during drilling and dumped at the west portal making a large flat area. There was a eastbound signal here #130.1 along with a phone box. On the east end there was a phone booth and a westbound signal, now all gone.
During construction of Western Maryland's Indigo Tunnel, a man who was working in the tunnel was injured when a timber fell on him. The man ended up in the hospitial and lost his leg. He later lived in Little Orleans after leaving the hospital. He worked for the Western Maryland as a "portal man" for 10 years in the very same tunnel where he had lost his leg. The man was replaced by his son, after difficulties incountered while working with a missing leg. The man's son worked the night shift as portal man at WM's Indigo Tunnel for over 44 years. He was responsible for maintaining the track in the tunnel, keeping them free of rocks and debris that may have fallen. One particular day during a severe downpour the man had checked one end of the tunnel and was at the other end when he heard a "terrific racket" at the end of the tunnel he had just checked. It turned out that a approaching train had hit a rock slide. The train had wrecked and the man was blamed for the accident. However, he was later cleared after an investigation proved "he could not have been at fault."