Mammoth Lakes is the sole incorporated town within Mono County, California, situated in the southwestern, mountainous region of the state. It lies immediately to the east of Mammoth Mountain at an elevation of 7,880 feet on the edge of the Long Valley Caldera. The area is geologically active, featuring hot springs and rhyolite domes less than a thousand years old. This high-altitude setting places it within the Eastern Sierra region of the Sierra Nevada mountains, surrounded by the Ansel Adams and John Muir Wilderness Areas.

The Mono people were the first settlers in the area thousands of years ago. European history began in 1877 when prospectors staked a claim on Mineral Hill, sparking a gold rush that brought 1,500 residents to the mining camp of Mammoth City by late 1878. Heavy snowfall and company shutdowns caused a decline, which accelerated after a fire destroyed half the settlement in November 1880. By the early 1900s, the town of Mammoth, now known as Old Mammoth, was informally established near Mammoth Creek with an economy based on logging and tourism.

The modern town developed after businesses relocated north from Old Mammoth following the completion of Highway 203 in 1937. The area is defined by its hilly terrain and high altitude, making it ideal for high-altitude athletic training among elite long-distance runners. Natural features include lakes, soda springs, an obsidian dome, and natural hot springs offering bathing opportunities. Lake Mary lies south of the town with recreation facilities, while Mammoth Mountain looms over the town to the west.

The economy is primarily tourism-based, serving as a resort town next to the popular skiing destination of Mammoth Mountain. The Mammoth Ski Museum opened in 2004, featuring vintage artifacts and photographs by founder Dave McCoy. Visitors utilize State Route 203 to access the ski area, Minaret Summit, and Devils Postpile National Monument. The town serves as a base for exploring the region, with rentals plunging in summer to make it an affordable hub for hiking and regional exploration.

As of the 2020 census, the population was 7,191, reflecting a decrease from previous counts. The median household income was estimated at $87,121 in 2023. Access is provided via Mammoth Yosemite Airport with flights to Los Angeles and San Francisco, or by car via US 395 and Interstate 80. The climate is warm-summer humid continental with long, snowy winters averaging 206 inches of snow per season. It was the snowiest place in North America during the 2022–2023 floods.