The Santa Ana River Watershed is a crucial ecological area located in Southern California. It covers approximately 2,650 square miles and includes parts of several counties, including Riverside, San Bernardino, Orange, and Los Angeles. The watershed is home to diverse habitats, supporting various plant and animal species, and plays a vital role in the region's water supply. The Santa Ana River, the main watercourse in the watershed, flows for about 100 miles from the San Bernardino Mountains to the Pacific Ocean. This river and its tributaries are essential for flood control, irrigation, and recreational activities. The watershed also faces challenges such as urban development and pollution, which impact its health and sustainability.