Cavern tours are offered seven days a week September through May. During the summer months, caverns tours are only offered on the weekends. Tour reservations are by mail and must be made 2 weeks in advance. A reservation form will be mailed to you at your request by calling (760) 928-2586. On busy weekends and holiday weeks, tours often sell out. Reservations are required for groups of ten or more. The park’s visitor center is located in the historic home of Jack and Ida Mitchell, who ran a resort here from 1934 through 1954.