The relationship between the occurrence of an algal bloom in a northern Utah lake and the corresponding availability of nutrients indicates phosphorous to be the limiting macronutrient. Feedlots surrounding the lake appear to contribute significant quantities of nutrient to the lake. Algal growth is initiated yearly with the release of phosphorous from the lake sediments. Coliform bacterial counts are shown to be qualitatively accurate diagnostically regarding fecal pollution but relatively useless for quantitative measurement of nutrients thus contributed. Aeration of the hypolimnion is suggested as a possibility for control of the algal bloom phenomenon. (Author)