Spruce Run Recreation Area is a 1,290 acre New Jersey state recreation area located in Clinton Township in Hunterdon County. It encompasses the Spruce Run Reservoir that is used as a backup reservoir to protect New Jersey from prolonged droughts. The reservoir is the third largest in the state, after Round Valley and Wanaque Reservoir. The reservoir is used for recreation purposes, including fishing, boating and swimming. Motors are limited to 9.9 horsepower.
At times of drought, Spruce Run feeds water into the nearby south branch of the Raritan River to supply water to more populated areas of the state downstream.
The Division of Fish and Wildlife supplies annually trout hatchlings to the lake for fishing. Other species that can be caught include largemouth bass, northern pike, smallmouth bass, carp, and channel cats.