There are now nearly three hundred geologic maps of southern and central California in the Geologic Maps Foundation library (a combination of mostly 7.5′ & 15′ quads). Plus, we've been adding a few miscellaneous out-of-print maps that benefit our field and geo-hikes activities.
Maps are free to view and download and are high-resolution .pdf files, https://geologicmapsfoundation.org/geologic-maps/
We are also developing a map app that will make field use easier and convey more geologic information.