Gunlock State Park in Washington County, Utah, lies about 15 miles northwest of St. George beside the 266-acre Gunlock Reservoir on the Santa Clara River. The dam was built in 1970 for irrigation and flood control, and the park grew around this lakeside setting as a primitive recreation area with facilities for camping, swimming, boating, and fishing. The park and reservoir are named for the nearby community of Gunlock, which honors William “Gunlock Will” Hamblin, the first settler there, a Mormon pioneer who arrived in 1857. His nickname reflected both his marksmanship and his skill repairing gunlocks. The park road follows the route of the Old Spanish Trail.