Bastrop Co.W side of Alum Creek floodplain ca. 300-500 ft. downstream from (SW) of crossing of Hoppy Spring Tract road, ca. 1.3-1.4 airmiles SE to SSE of jct. St. Rt 21 and F. M. 1441 NE of Bastrop. Bastrop State Park. Smithville NW Quadrangle, Texas, United States, North America