The Washita Headwaters Watershed (HUC 11130301) covers approximately 1,584 square miles in southwestern Oklahoma. It is part of the larger Red River Basin and is characterized by rolling hills, grasslands, and forested areas. The hydrology of the watershed is influenced by precipitation, which is generally higher in the east than in the west, and by the Washita River, which runs through the center of the watershed. The watershed receives an average of 26 inches of precipitation per year, with snowfall occurring in the winter months. Surface water resources in the watershed include Lake Altus-Lugert, which provides drinking water and recreation for the area. Reservoir constituents include dissolved minerals and organic matter, which can impact water quality. Interesting climatic facts and trends include increasing temperatures and changes in precipitation patterns, which have the potential to affect water availability and quality in the watershed.