Adapted from Yosemite National Park by Jeffrey P. Schaffer

For overnight stays in the backcountry, you need a wilderness permit. If you are visiting from November through April, there are no reservations; you register in person. For the appropriate location to register, see the"Wilderness Permits" section at the start of each hiking chapter (Chapters 5, 6, 7, 8, 9, 10, 11, and 12). For the rest of the year you can make reservations, although for most trails and destinations, you can probably do so successfully in person, since their quotas likely will not be full. However, popular destinations, such as Lyell Canyon, the Cathedral Lakes, the Vogelsang Lake area, and Little Yosemite Valley, can easily reach their quotas, especially for overnight trips beginning on a summer weekend. Therefore, you might want to get a permit well in advance, especially if you are hiking on a summer weekend.

You can get a permit from 24 weeks to 2 days in advance of your trip date. In theory, you can also get a permit by calling the Wilderness Center at (209) 372-0740, but the reservation phone lines are often busy, and you may not get through. Therefore, you are encouraged to make your request in writing. Written requests are processed simultaneously with phone requests. Write to: Wilderness Permits, P.O. Box 545, Yosemite, CA 95389. Include the following in your request: name, address, daytime phone, number of people in party, method of travel (i.e., ski, snowshoe, foot, horse), number of stock (if applicable), start and end dates, entry and exit trailheads, and principal destination. Include alternate dates and/or trailheads. A $3 per person non-refundable processing fee is charged for all reservation requests. Payment by check or money order should be made to the Yosemite Association. Credit card payments are accepted with valid card number and expiration date.