Emigrant Dam and Lake, located 7.5 miles southeast of Ashland, Oregon, on Emigrant Creek, was constructed by the Talent Irrigation District for irrigation water supply. The original 110-foot-high thin-arch concrete dam was incorporated into a 204-foot-high earthfill structure with enlargement by the Bureau of Reclamation in 1961. The dam is 204 feet high and has a crest elevation of 750 feet. The reservoir’s total capacity is 40,500 acre-feet (active 39,000 acre-feet). The enlarged reservoir reregulates Green Springs Powerplant discharges and provides additional storage for irrigation.
Most of the rock layers consist of medium to fine-grained sandstone, but layers and lenses of siltstone, claystone, conglomerate and coal are present throughout the series. Into these sediments many irregular sills and dikes of diorite, andesite and felsite have been intruded. The color of the rocks range from light gray to black, most layers are reddish to yellowish brown.