A one-month synoptic study of the limnological characteristics of the Big Cypress Swamp, Florida, was conducted in March 1970. This study was undertaken to insure that as much information as possible would be available on water quality to serve as background in an effort to develop recommendations on the need to maintain special protection areas in the Swamp. Thirty-four sampling stations were established throughout the Big Cypress. The waters were examined for physical, chemical, and biological characteristics. Special attention was directed to evaluation of the water quality impact of typical urban, agricultural, and other development in the study area.