Big Basin Redwoods State Park is a state park in the U.S. state of California, located in Santa Cruz County, about 36 km (22 mi) northwest of Santa Cruz. The park contains almost all of the Waddell Creek watershed, which was formed by the seismic uplift of its rim, and the erosion of its center by the many streams in its bowl-shaped depression.

Santa Cruz County, officially the County of Santa Cruz, is a county on the Pacific coast of the U.S. state of California. As of the 2020 census, the population was 270,861. The county seat is Santa Cruz. Santa Cruz County comprises the Santa Cruz–Watsonville, CA Metropolitan Statistical Area, which is also included in the San Jose–San Francisco–Oakland, CA Combined Statistical Area. The county is on the California Central Coast, south of the San Francisco Bay Area region. The county forms the northern coast of the Monterey Bay, with Monterey County forming the southern coast.