Rangers are assisting callers between 8 a.m. and 5 p.m. daily. To help alleviate the volume of calls and subsequent busy signals, fax your completed reservation request at least 7 days in advance of your trip. Be sure to include accurate day, evening, and fax numbers on your request. Reservations are available during the use limit season of May 1 through September 30 only, and are not available for other times of the year. One itinerary change or readjustment before and during one's trip is permitted without additional charge.
Reservations are optional.
They are often not needed, especially early and late in the summer and on some weekdays during mid summer, or if you keep your options very flexible upon arrival in the park. Poor weather also radically affects demand. However, climbers and backpackers are generally advised to make reservations for weekend climbs and backpacking trips, including Friday nights. Those going on extended backpacking trips are also advised to make reservations. Reservations may be requested no earlier than April 2 for trips starting June 2.