While it is not always required to have a reservation for camping at Mammoth Lakes, it is highly recommended, especially during peak season. Many campgrounds in the area accept reservations, while others operate on a first-come, first-served basis. To secure a spot and avoid disappointment, it's best to make a reservation in advance. You can find a variety of camping options in Mammoth Lakes, including cabins, lake, desert, and forest camping, on Hipcamp.