TO MAKE RESERVATIONS AT CALIFORNIA STATE PARK campgrounds, including the one at Hearst Castle, call 1-800-444-7275. You can reserve family and group campsites up to seven months in advance.
* DETROIT CELEBRATES CENTENNIAL (1896-1996) OF U.S. automotive industry. Among the centennial festivities will be these car club gatherings: Antique Automobile Club of America, June 17-23; Walter P. Chrysler Club, July 10-15; Lincoln and Continental Owners Club, Sept. 12-16; Crown Victoria Association, July 29-Aug. 3; U.S. Camaro Club, Aug. 8-11; Hudson-Essex Terraplane Club, July 24-28; International Mercury Owners Association, July 12-14.
Among the city's automobile-related sites: The Henry Ford Museum and Greenfield Village, 20900 Oakwood Blvd., Dearborn, 313-271-1620, open daily 9 a.m. to 5 p.m.; Ford Motor Co. Wixom Assembly Plant 810-344-5358 builds Ford luxury cars. Request a tour in writing, well ahead of your planned visit, including the number of people in your party. Send your request to Plant Tours, Ford Motor Co., Wixom Assembly Plant, 28801 Eixom Road, Wixom, MI 48393-0001. Free; Henry Ford Estate in Fair Lane, 4901 Evergreen Road, Dearborn, 313-593-5590. Tour times vary. Admission fee; lFisher Mansion, 383 Lenox, Detroit 313-331-6740, Fri.-Sun., 12:30, 2, 3:30 and 6 p.m., admission fee.
For a free packet of information, including a fun lovers coupon book, a calendar of events, and a Detroit Visitors Guide, call 1-800-DETROIT.
* CEZANNE IN PHILADELPHIA. In conjunction with the Cezanne Exhibition at the Philadelphia Museum of Art, May 30-Sept. 1, which will display more than 110 oil paintings and 80 watercolors and drawings, 15 Philadelphia hotels are offering Cezanne packages that include VIP passes to the exhibition. The VIP passes are available only with the hotel packages. In addition, the packages include one night of accommodations, admission to the Museum of American Art, parking and breakfast. The hotel rates range from $149 to $279. For a Cezanne exhibit and hotel package brochure, call 1-800-752-8206.
* BOSTON CELEBRATES THE FOURTH OF JULY in a big way. More than 125 events take place from July 2-7 including concerts, cruises, walking tours, maritime displays, re-enactments and fireworks. 617-227-1528.
Other Massachusetts events include the Old Deerfield Summer Craft Fair June 22 and 23, 413-774-7476; the Hyannis Boat Parade July 4, 800-4-Hynnis; the Brimfield Outdoor Antique Show July 9-14, 800-628-8379; the American Artisans' Crafts Show, July 13 and 14 in Pittsfield, 413-443-0188; and the Lowell Folk Festival, July 26-28, 508-970-5000. To request information about Massachusetts, call 800-447-MASS.
* A HOSTELLING INTERNATIONAL hostel has opened in Hurricane, Utah. The Dixie Hostel, 73 S. Main St., 801-635-8202, has 28 beds, laundry facilities and parking. The overnight fee for HI members is $15; private rooms for families or couples are $40. Other new hotels in the United States include one on North Carolina's Outer Banks at 1004 West Kitty Hawk Road, Kitty Hawk. The former schoolhouse has 53 beds, including couple and family rooms that can be reserved in advance. A new hostel in Sonora, on the campus of Columbia College, is 40 miles from Yosemite National Park. The address is 11800 Columbia College Drive, 209-533-2339.