Monahans Sandhills State Park, State park in western Texas, United States.

Monahans Sandhills State Park covers 3,840 acres in Ward and Winkler counties, Texas, where dunes reach up to 70 feet high. The sand is almost pure quartz, with grains averaging under 0.22 mm across. Ridges run in rounded crests, lit slopes pale gold and lee slopes dark brown, with fine wind ripples on the lower slopes and dry grass stalks along the crests.

The park opened to the public in 1957, managed by the Texas Parks and Wildlife Department. Most of its land lies on a ranch held under a 99-year lease with the Sealy-Smith Foundation, giving the state leasehold rights to the sand hills until 2056. The sandhills sit within the Permian Basin, and some oil production continues in and around the park.

The park lies in the Permian Basin, and oil production continues in and around it, so pump jacks can be seen among the dunes. Visitors today use the sand for sandboarding, sand surfing, sand tobogganing and sand football, sliding down slopes that reach 70 feet.

The park lies off exit 86 of Interstate 20, near Monahans in Ward and Winkler counties. Its 3,840 acres hold dunes up to 70 feet high, so allow time to walk the ridges; the semi-arid climate averages only 12.3 inches of rain a year. Sand gets hot under strong sun, and the Havard oak groves that hold dunes in place are fragile.

A small shrub called the Havard oak grows here and develops deep underground roots that reach water far beneath the sand. While the plant stays tiny above ground, its root system spreads far below the surface to survive in this dry environment.