The following airports do not have control towers, but are listed by their owners as open to the public. Pilots announce runway and airspace usage via radio contact. These airports have Class E airspace for those with an FAA-published instrument approach procedure, or Class G airspace otherwise.
Fremont Airport (identifier Q59) in Fremont, California
Montgomery Field / Marina Airfield, now called Marina Green (Airmail Facility), San Francisco, California, formerly named after aviation pioneer John Joseph Montgomery
Sky Sailing Gliderport in Fremont California
Vacaville Airport/Vacaville Gliderport, in Vacaville, California