In Daly City, at the end of Thornton Beach Road. Follow John Daly Boulevard west from Interstate 280 across Skyline Boulevard into Thornton State Beach.
From Skyline Boulevard, turn west at the intersection with John Daly Boulevard into Thornton State Beach. From the parking area or the stables, proceed to the dunes on old Thornton Beach Road. The Bay Area Ridge Trail begins where the road meets the dunes.
The climate is Mediterranean, so it tends to be windy and cold throughout much of the park. During the summer months, fog is common along the coastlines. Dress in layers is recommended. Hiking boots are appropriate in some areas.