On at least USGS quads, the data are older than that. They are still very useful. Aerial photos came into mapping big time with the advent of WWII, and maps made since that time need updating of their cultural features, but the terrain remains constant.

The current maps for the California Channel Islands date from 1943, when the US military thought it might be useful to obtain accurate maps of coastal regions, and the topography is right on. I used those maps intensively for fifteen years - they were fully satisfactory.