The third annual Fifties Festival at Deer Valley will be held Saturday, beginning with an auto show at 10 a.m. and winding up with a '50s-style sock hop in Park City that night. In between, there'll be a concert featuring Chuck Berry, exhibits of 1950s memorabilia and excerpts from "Grease."

Berry's concert, scheduled to begin at 5 p.m. at Deer Valley Resort, stars one of the legends of the rock 'n' roll era. More than 30 years after the birth of rock 'n' roll, Berry's music, lyrics and free spirit continue to make an indelible impression on young music lovers. Even later performers - including the Beatles and the Rolling Stones - were influenced by Berry's style."You begin to wonder where today's bands would be, had there never been a Chuck Berry," says Roy Hollingworth of Melody Maker magazine.

Adds Jim Delehant of Hit Parader, "(Berry) showed everyone how to adapt boogie-woogie and blues to rock and roll."

The Fifties Festival, co-sponsored by Deer Valley and KALL-910 Stereo starts at 10 a.m. Saturday with the car show at Snow Park Lodge. Nearly 75 cars from the 1950s will be shown, with judging in five categories: pick-ups/panels; restored; custom, street machines; and miscellaneous. Trophies will be awarded to the top three in each category, along with a People's Choice Award to the overall favorite vehicle.

At noon, the memorabilia exhibit will open and the box office will open for the Chuck Berry concert.

At 2 p.m., the vintage cars will be paraded through Park City, after which the "Grease" revue will be presented at City Park.

Appearing with Berry will be the Disgusting Brothers.

Tickets are priced at $14 in advance and $16 on the day of the concert. Advance tickets are available at Smith'sTix outlets and Jans Mountain Outfitters.

For details on group rates and/

or overnight lodging packages, contact the Stein Eriksen Lodge at 649-3700.

The celebration will conclude with a sock hop and dance contest at 9 p.m. at Steep's, located at the base of the Park City ski area. Deuce Desoto and the Deadweights will perform music of the era. Dance admission is $5.