Fish to eighteen inches are regularly caught. The best luck comes when you practice good technique here. Very productive river fishing. The San Joaquin river begins at Thousand Island Lake, ten miles north of Mammoth, and ends up in the San Francisco Bay. Lose something in the river and you can look for it there.
Most fish here are around twelve inches, but a few bigger have been caught.
During the summer there is a shuttle that takes you down into the valley. Up HWY 203 past Mammoth Mountain and down Minaret Road to Agnew or Red's Meadow. This road is also an excellent bike ride for those who would like to overdo something. There are sections of wild trout river, and sections where anything goes. During the winter if you pick a good day you'll have as much fun as during the middle of summer.