This website is by no means the end-all, be-all of getting out into nature on transit. Some other resources that I’ve found continually helpful for myself have been:
Marin Transit: Transit to Parks: Marin Transit’s official page detailing the Marin-area parks their services run to
Transit Trekker: another transit hiker who has put together links to resources like this one, for cities across the country
California Public Lands map: a map from CalFire showing all of the public land in the state
Climate Action Center - Bikes on Transit Information: Want to take your (e)bike on transit to help you go farther and see more? This site has detailed bike-friendliness information on each of the operators in the Bay Area