EAST FORK OF THE TRINITY RIVER. The East Fork of the Trinity River rises 1½ miles northwest of Dorchester in south central Grayson County (at 33°32' N, 96°41' W) and runs south for eighty-five miles, across parts of five northeast Texas counties, to its mouth on the Trinity River, five miles northeast of Bristol in western Kaufman County (at 32°29' N, 96°30' W). The stream is intermittent in its extreme upper reaches. It crosses into Collin County seven miles southeast of Gunter. In Collin County it passes just east of McKinney and enters Lavon Lake five miles southeast of McKinney. The East Fork exits the reservoir two miles west of Lavon and then enters Lake Ray Hubbard. As part of the lake, it enters Rockwall County three miles northwest of Rockwall and subsequently crosses into Kaufman County. The stream traverses flat to rolling prairie with occasional steep slopes, surfaced by clays and sandy and clay loams that support oak, juniper, water-tolerant hardwoods, conifers, and grasses. The region has served as range and cropland, although urban development and local mineral production were present by the late 1900s. The nine tributaries of the East Fork include Stanley Creek, Hurricane Creek, and Long Creek.