The Tuolumne River is a major river located in the Sierra Nevada mountains of California. It flows for approximately 150 miles, starting from the Tuolumne Meadows in Yosemite National Park and eventually joining the San Joaquin River. The river is known for its clear waters and stunning scenery, making it a popular destination for outdoor activities such as fishing, rafting, and hiking. The Tuolumne River is also significant for its role in providing water for irrigation and municipal use in the surrounding areas. It is part of the Hetch Hetchy water system, which supplies drinking water to the city of San Francisco. The river's ecosystem supports various wildlife and plant species, contributing to the region's biodiversity.