The Long Valley Caldera is a large volcanic depression located in eastern California, formed by a massive eruption about 760,000 years ago. This caldera is approximately 20 miles long and 10 miles wide, making it one of the largest in the United States. It is situated near the eastern Sierra Nevada mountains and is known for its geothermal activity, including hot springs and fumaroles. The caldera is also home to the Mammoth Mountain, a prominent volcanic peak that rises above the surrounding landscape. The area is rich in natural beauty and offers various recreational opportunities, such as hiking, skiing, and fishing. The Long Valley Caldera is an important site for studying volcanic activity and understanding the geological history of the region.