I know some of the trailheads in Altadena and the Santa Monica Mountains can be reached by bus, but I usually have to drive to hike in L.A. and had trouble offering suggestions beyond those. Thankfully, the L.A. Metro is stepping in to help.
The Source, L.A. Metro’s blog, has started a series of trail write-ups for hikes you can get to using only mass transit, starting with Temescal Canyon. It’s a wonderful idea and I look forward to future entries for my transit-minded friends. I hope you don’t mind wearing your backpack on the bus!