The Upper Malheur watershed covers an area of approximately 1,900 square miles in eastern Oregon. The hydrology of the watershed is characterized by semi-arid conditions, with much of the precipitation falling as snow in the winter months. The snowpack in the watershed is an important source of surface water during the warmer months, and is closely monitored by the state for water management purposes. Surface water in the watershed is primarily found in the Malheur River and its tributaries, which are used for both agricultural and recreational purposes. There are several reservoirs in the watershed, including the Beulah Reservoir, which is used for irrigation and water storage. The climatic trends in the watershed have shown a decrease in snowpack and an increase in temperature over the past few decades, which has implications for water availability and ecosystem health.