Map of the Paluxy Artesian Reservoirs of the Black and Grand Prairies of Texas including the Eastern and Western Cross Timbers

This map shows a portion of Texas with shadings in different colors to represent depths of reservoirs. In the top, left-hand corner, there is an inset showing the entire state and marking the area detailed in the map. The header at the top of the map says, "U. S. Geological Survey, Twenty-First Annual Report, Part VII, PL. LXX." Scale [1:316,800] "Contour Interval 100 feet.