The majority of the 500 campsites in the park are available by reservation only from September to May. Reservations can be made up to 6 months in advance, and can be booked on recreation.gov. Reserving a site is highly recommended if you are planning to camp on a holiday, a weekend, or anyday of the week in the spring. Our busy spring season runs from from February to May. Reservations for group sites may be made up to 6 months in advance.