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Indigo Tunnel
Historic Site
The Indigo Tunnel, carved into the rugged hillsides near Little Orleans along the Potomac River, emerged in 1904 as part of the Western Maryland Railway?s ambitious Cumberland Extension, a project that pushed rail service westward through a landscape dominated by the long rivalry between canal and rail transport. Stretching 4,350 feet, it was the longest tunnel on the line and allowed trains to bypass a particularly winding section of the river valley, improving efficiency for both freight and passenger service and saving a mile or more of track. The line opened to traffic in 1906 and operated until 1975, when changing transportation patterns led to its abandonment. In the decades that followed, the tunnel drew interest as a potential link in the Western Maryland Rail Trail, but the discovery of a significant bat colony shifted its future toward conservation. Today, the tunnel remains closed and protected, with gated portals preserving its ecological value while its historical role endures in the broader story of railroads threading through the Potomac River corridor.
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Contact Information
C&O Canal National Historical Park
142 W. Potomac St.
Williamsport MD 21795
301-739-4200
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