The Lower Heart Watershed, also known as HUC 10130203, covers a land area of approximately 3,248 square miles in Montana, United States. This area is characterized by cold winters and warm summers, with average annual precipitation of 12 inches. The hydrology of the area is mainly influenced by snowpack, which feeds into the Lower Heart River and its tributaries. The surface water quality is generally good, with low levels of pollutants due to the rural nature of the area. The reservoirs in the watershed are used for irrigation and recreation purposes, but do not contain significant levels of pollutants. Interesting climatic facts and trends include increasing temperatures and changes in precipitation patterns, which may affect the snowpack and water availability in the area. Overall, the Lower Heart Watershed is an important source of water and ecosystem services for the surrounding communities.