Report 26 by Willard B. Mills, United States Geological Survey | August 1966
- Report 26 - Base-Flow Studies Big Elkhart and Little Elkhart Creeks Trinity River Basin, Texas: Quantity and Quality, September 15-16, 1965 (pdf - 4.67MB)
- Figure 5 - Geologic Map of the Big Elkhart and Little Elkhart Creeks Watersheds