Cuyamaca Rancho State Park, Nature reserve in San Diego County, United States

Cuyamaca Rancho State Park is a nature reserve in San Diego County featuring meadows, forests, and streams across multiple elevation zones. The landscape supports different ecosystems, with the highest point at Cuyamaca Peak.

The property became a state park in 1933 when Ralph Dyar sold his land to California, opening his former summer residence to the public. This transition converted the area into a protected recreation space.

The park's name comes from the Kumeyaay word "Ekwiiyemak", referring to the area behind the clouds. The Stonewall Mine exhibit recalls the Southern California gold rush, when miners worked gold-bearing quartz in the Julian Schist. Visitors can still see the mine's remnants among the pines and oaks.

The park offers camping sites, hiking trails suited to different abilities, riding paths, and mountain biking routes throughout its grounds. A visitor center provides information and educational resources about the natural features and activities available.

Gold was mined at the Stonewall Mine, and an exhibit there explains the operation today. Most streams in the park still carry small amounts of gold, washed out of quartz exposures by weathering. The mine sits among schist, gneiss and quartzite of the Julian Schist, the rock that hosted the gold veins.