These circulars issued from the Bureau of Economic Geology contain the record of cores and cuttings from well received and described in the Bureau. In some instances, driller's logs and other data are given, although it is usually impracticable to include logs of all wells, the logs given being selected as representative of the county or area to which the circular relates. The elevations given are for the most part those reported with the driller's log. In some instances the elevation given, as indicated, is that obtained from the location of the well on the topographic map.

Uvalde County is located in southwestern Texas, including part of the north margin of the Gulf Coastal Plain and the south margin of the Edwards Plateau. Its principal mineral resources are asphalt rock, clay, limestone, gravel, trap rock, and surface and underground water. Some shows of oil and gas have been found at several localities, and small production of oil has been obtained on the Pulliam ranch in the southern part of the county.