Davidson Ditch is a 90-mile (140 km) conduit built in the 1920s to supply water to gold mining dredges in central Alaska. It was the first large-scale pipeline construction project in Alaska, and lessons learned in its construction were applied to the building of the Trans-Alaska Pipeline System. It is eligible for inclusion on the National Register of Historic Places, but has not been listed due to a lack of information. Despite this, the remains of the conduit are partially protected by its inclusion in the White Mountains National Recreation Area.