Ray Roberts Lake State has a total of 5,848.8 acres. All properties were acquired in 1984 by a lease made between the Secretary of the Army and the Texas Parks and Wildlife Department.

Park, Isle du Bois Unit, is on the south side of Ray Roberts Lake in Denton County. Isle du Bois Unit (meaning "Island of the Trees") opened in 1993.

Ray Roberts Lake State Park, Johnson Branch Unit, is located on the north side of Ray Roberts Lake in Denton and Cooke Counties. This unit opened on December 4, 1996.

The lake was created to provide water to the Cities of Dallas and Denton. Ray Roberts Lake, authorized by the Rivers and Harbors Act of 1965, takes in portions of three counties: Denton, Cooke, and Grayson. Originally known as the Aubrey Reservoir, the lake was named in 1980 for former Congressman Ray Roberts (1913-1992) of Denton. The lake is a 29.350-acre Corps of Engineers impoundment on the Elm Fork of the Trinity River.

• Anglers! The current lake record for largemouth bass is 14.06. Crappie, white bass, and catfish are also a good catch.
• Equestrians -- take your horse along the 12.5 miles of dirt trails, but watch out for the notorious diamondback rattlesnake. Camp at one of the many equestrian sites that Isle du Bois offers.