PARK CITY, Utah (AP) _ President Clinton and his family celebrated daughter Chelsea's 18th birthday in private Friday at a borrowed mountaintop home adjacent to ski slopes.

The birthday girl and first lady Hillary Rodham Clinton spent the morning skiing in apparent anonymity, despite the skiing Secret Service agents that shadowed the pair. A network TV crew that had set up shop in the busy lodge at Deer Valley ski area did not spot the ladies all day.

They planned a birthday dinner out of the public eye.

``That's what private time is about,'' said Marsha Berry, a spokeswoman for Mrs. Clinton. She and other White House aides refused to divulge any details of the first family's mini-vacation.

The president had said earlier that he would not be skiing _ he tried it once 14 years ago and injured a knee _ but would instead relax with a book at the home of Hollywood executive Jeffrey Katzenberg, who lent the Clintons his gated, multimillion-dollar digs for the weekend.

The small contingent of White House aides traveling with the Clintons took advantage of the boss' seclusion and scurried to ski rental shops and chair-lift lines.

Last year, for Chelsea's 17th birthday, her parents took her and several girlfriends to New York for two hit Broadway musicals and a slumber party at the Waldorf Astoria.

Deer Valley Resort, where the Clintons are staying, was busier than normal for a Friday.

``I don't know if it's related to the first family being here or not,'' said resort spokesman Dirk Beal. He said a more likely reason for the projected 4,200 skiers he was serving Friday was the 30 inches of new snow that had fallen since Tuesday. More snow was falling there Friday.

People at the resort had mixed feelings about the Clintons being nearby.

``I see them enough on television,'' said Elaine Goldberg of Marina del Rey, Calif. However, she admitted she'd be thrilled if she happened to bump into them on the slopes.

Another person who wouldn't mind seeing them was 21-year-old Clinton Stocking, a Deer Valley employee who ferries skiers from their cars to the resort's lifts: ``I wanted to give them my name badge and say, `Hey, my name is Clinton.'''