The Mattole Watershed covers approximately 304 square miles in northwestern California. It is characterized by steep terrain, high rainfall, and a temperate climate. The watershed is fed by several creeks and streams that originate in the King Range Mountains and flow into the Pacific Ocean. Snowpack in the region is generally low, with the majority of the precipitation falling as rain. Surface water in the watershed is highly variable due to the region's Mediterranean climate and seasonal precipitation patterns. The largest reservoir in the area is the Mattole River Estuary, which provides habitat for various species of fish and wildlife. Interesting climatic facts and trends include the region's susceptibility to drought, and the potential impacts of climate change on the availability and quality of water resources in the watershed.