Joseph D. Grant County Park

Joseph D. Grant County Park is Santa Clara County's largest regional park, covering 10,882 acres at the base of Mt. Hamilton. Its centerpiece, Halls Valley, lies between two ridges of the Diablo Range, and the terrain was shaped by movement along the still-active Calaveras Fault. Grasslands and oak woodland of blue, black, live, and valley oaks support more than 32 bird species and 39 mammal species. Cattle grazing is part of the park's history and is still used to manage some areas, and the park once hosted a successful program to increase Tule elk numbers. Spring brings wildflowers and running water.

A 51-mile trail system is open to hikers and equestrians, and mountain bikes are allowed on more than 75% of the trails. Dogs on a 6-foot leash may use the trails, picnic areas, and campgrounds. There are shaded first-come, first-served picnic areas, reservable group picnic and youth camping areas, and almost 40 reservable family campsites with hot showers for campers. One large lake and several smaller ponds offer warm-water fishing. Fires are allowed only in designated fire rings, and gathering wood is prohibited.

Agents of Discovery, a free mobile game in English and Spanish, starts near the historic ranch house and follows the Hotel and Snell trails for more than 1.5 miles. Up the mountain, Lick Observatory holds monthly concerts, lectures, and telescope viewings. The park is open from 8 a.m. to sunset, with vehicle entry fees year-round and additional fees for camping and group picnic areas. The Grant Lake entrance on Highway 130 has free parking.