Howard Prairie Dam is a zoned earthfill structure, with a height of 100 feet and a crest length of 1,040 feet that contains 416,000 cubic yards of material. The reservoir created by the dam has a total capacity of 62,100 acre-feet (active 60,600 acre-feet). The dam is on Beaver Creek, 18 miles east of Ashland, Oregon.
The damsite geology consists of hard fresh medium grained basalt, about 29 feet thick, underlies the relative thin mantel of sandy topsoil. Unconformably underlying the basalt are lacustrine and aeolian deposits. On the left abutment, this deposit is a tuff breccia about 30 feet thick; on the right abutment these deposits consist of claystones, siltstones and diatomite as tuff and tuff breccia.