Water-level data in table 1 are from wells that are measured annually, prior to the irrigation season to achieve the most natural representation of the static water level. Water level measurements listed in the column under 1976 may have been made during December 1975 or January, February, March, April, or May 1976. Measurements listed in the column 1977 may have been made during December 1976 or January, February, March, or April 1977. Figure 1 shows the counties and number of wells therein, where data were obtained for this report.
Records of water levels in Oklahoma are collected through a cooperative program by the U.S. Geological Survey and the Oklahoma Water Resources Board. The records are tabulated and published by the U.S. Geological Survey on an annual basis.