Big Basin has the largest redwoods and most extensive old-growth trail system in the Bay Area, but a major fire burned through in 2020 and the park isn’t expected to be fully open until about 2030.

A nice quiet park that appears to be mostly old growth, but the trees are pretty small. Has a small campground. The Peters Creek grove is the most impressive in the park, but it requires a long and difficult hike.

The busiest redwood park, mainly because it’s close to San Francisco. The old-growth grove is very scenic, although the redwoods aren’t especially large. Reservations are required to park anywhere near the entrance.

Features a small and very popular old-growth grove just outside Santa Cruz. The park also has a campground and an extensive second-growth trail system.

A remote, redwood-blanketed cluster of parks with some very nice second-growth trails. There are also a few patches of old growth, most notably tiny Heritage Grove.

A quiet, remote park with a remarkably lush pocket of redwoods in a coastal canyon. The canyon bottom, where the biggest redwoods were, has been heavily logged, but some old growth uplands remain.

A scenic and enjoyable park in a lush redwood-filled gorge. The Pioneer Tree Trail has a tiny but nice old-growth grove; the rest of the park is second growth.

It’s not in pristine condition, but Roy’s Redwoods has what appears to be a small, off-trail old-growth grove.