Cogswell 1949 Cinclus mexicanus 1. Apr. 9 - Lumsden Bridge, 1875' alt., middle fork of Tuolumne River, Tuolumne Co., Calif - a nest (in use, according to T. Wimby) was seen from the downstream side of the bridge. It was placed on a slight ledge in an almost vertical rock wall (with no other ledges) about 8 ft. above the water, with nest entrance facing the stream. Apr. 10 - Jawbone Creek, 3400' alt., Tuolumne Co., Calif. I heard calling as it flew downstream at 5:40 AM. margins of creek well-wooded; water nearly clear, stream about 15 feet wide with many jutting rocks & few logs in it.