Lake Bruin is an ox-bow lake of the Mississippi River located in Tensas Parish in northeastern Louisiana. It consists of some 3,000 acres (12 km2) of unusually clear water, particularly suited for swimming, boating, and fishing. Part of the lake is owned by the state, which operates Lake Bruin State Park, one of nineteen Louisiana state parks. Much of the land beside the lake is in private hands, and many fashionable homes, both vacation houses and permanent residences, have been constructed there in recent years. Many of the homes have piers extending into the lake.
Lake Bruin is the ox-bow lake for the St. Joseph area. Other ox-bow lakes include Lake St. Joseph, located in Newellton and across the highway from the nearby Winter Quarters State Historic Site, and Lake St. John near Waterproof.
Lake Bruin is named for Peter Bryan Bruin (1756-1827), a native of Winchester, Virginia, who owned a large plantation on the shores of the lake and resided there for a number of years after 1807. He is interred near Bruinsburg in Claiborne County, Mississippi.
Former State Senator Clifford Cleveland Brooks in 1920 purchased the Botany Bay plantation on Lake Bruin. He served in the Senate from 1924 to 1932. After Brooks' death in 1944, his widow continued to operate the plantation.
Area district attorney Jefferson B. Snyder, a St. Joseph native, maintained for many years a popular hunting lodge on Lake Bruin where he entertained governors, U.S. senators, surgeons, publishers, architects, even local bootleggers and African Americans in various occupations.