During the summer months of 1982 and 1983, aninvivo, flow-through, fluorometric method was used to obtain chlorophyllaestimates on a synoptic basis from the upper euphotic zones of two Oklahoma reservoirs (Grimshaw et al. 1985). SYMAP, a computer-based mapping routine was used to generate a total of 73 synoptic chlorophyll isopleth (chloropleth) maps for these reservoirs, and reservoir areas containing persistently high chlorophyll concentrations were delineated statistically. Serial chlorophyll mapping was effective in delineating sources of nutrient pollution, and proved useful in the development of efficient, cost-effective, sampling programs. The greatest strength of the method lies in its suitability for use on water bodies which have not been previously characterized limnologically. Its use permits a rapid transition from descriptive to experimental limnology for water bodies lacking a history of limnological research.