At about 1100 Pacific time, a Cessna 185A was damaged while making a low approach to Santa Paula Airport and subsequently was further damaged while making a precautionary landing in a nearby dry riverbed. The pilot departed Fresno at about 0930, but encountered low clouds upon arriving at Santa Paula. He was making a climbing right turn to get out of the clouds when he heard a loud bang. He then discovered the right gear was missing. Because of the narrow runway at Santa Paula, he landed in a nearby riverbed, at which time the left gear leg struck a stump.