Monahans Sandhills State Park consists of 3,840 acres of sand dunes, some up to 70 feet high, in Ward and Winkler Counties, about a half-hour's drive west of Odessa. The park is only a small portion of a dune field that extends about 200 miles from south of Monahans westward and north into New Mexico. Most of these dunes are stabilized by vegetation, but the park is one area where many dunes are still active. Active dunes grow and change shape in response to seasonal, prevailing winds. Activities include camping; hiking; picnicking; horseback riding; bird and wildlife watching from the interpretive center windows, which overlook watering stations; and sand surfing.