Mark Wilmer Pumping Plant, the first pumping plant on the CAP system, lifts water approximately 800 feet into the seven-mile long Buckskin Mountain Tunnel.

The tunnel was bored from both ends by a 23.5 foot diameter “mole” and fully lined with precast, 22 foot radius inside diameter segments. It was under construction from 1975 to 1980 and cost $65.8 million to construct, $2 million more than Mark Wilmer Pumping Plant.