Ash Hollow State Historical Park, 4265 US 26 about 3 miles south-southeast of Lewellen, takes in about 1,000 acres where the Oregon, California and Mormon trails dropped into the North Platte valley. Nine miles of trail on four routes lead to the wagon-rut swales of Windlass Hill; Ash Hollow Cave, a National Historic Landmark, is shown behind glass, and a 1903 rock schoolhouse is open for tours. Visitor center May 1–October 30, Thursday–Monday 10–4 Mountain; winter by appointment, (308) 778-7708. Grounds open 8 a.m. to sunset. Admission $5 (13 and over), $1 (ages 3–12), plus a park entry permit. Phone (308) 778-5651.