The Lake of the Arbuckles is the larger of the park's two reservoirs, covering more than 2,300 acres in the western half of the Chickasaw National Recreation Area. It is the busiest part of the park in summer — boating, fishing, swimming, water-skiing and tubing are all permitted and there are three developed campgrounds (Buckhorn, The Point and Guy Sandy) on its shores.
Fishing is the main draw. The lake is stocked with largemouth bass, white bass, crappie, catfish and bluegill, and a marina at Buckhorn rents small boats. The shoreline is rocky in places, with bluffs and small coves rather than long beaches; the best swimming is at the developed beach at the Point campground. Boat ramps are open year-round.