Radio Ridge is a block caught up in the San Andreas Fault zone -- the ridge has been uplifted within the zone due to either compression or lateral displacement (or both).  Looking southwest from Radio Ridge you can see the extension of the San Andreas Fault through the valley.  The fault continues to the northeast of the ridge where Bird Creek flows.  Bird Creek is an offset stream.  It flows northeast to the west of Radio Ridge where it hits the San  Andreas Fault and then makes a right-angle turn (about where Lodge Lake sits) and flows to the north of Radio Ridge and then makes another right-angle turn and flows northeast again down the valley to the northeast of Radio Ridge. The creek has a clear right-lateral offset.