The reservoir is an impoundment of Scoggins Creek, which drains a small portion of the eastern side of the Northern Oregon Coast Range.

[5] The lake is named for Henry Hagg, an Oregon dairy farmer who was active in local agricultural committees during the first half of the twentieth century.

[6] Scoggins Dam was built in 1975 by the United States Bureau of Reclamation, which still owns and operates the facility.

[4] Other users include four cities and the Tualatin Valley Water District.

This Washington County, Oregon state location article is a stub.