The two front-runners have something else in common -- the 21-year-old Creamer was the LPGA Tour's Rookie of the Year in 2005 and the 19-year-old Park already has clinched the honor this year.
Park, who was born in Brazil and moved with her parents to Los Angeles when she was 8, said she was nervous but thrilled to be in the tournament.
'I don't know how to describe the feeling, coming out here,' she said. 'Obviously being one of the top 20, elite members of women's golf, is a very priceless experience. And especially to be the only rookie out here gives me great pride and gives me a lot of confidence.'
Creamer had her irons clicking during her bogey-free round.
She said getting up and down from 115 yards for a par on the second hole seemed to steady her, and she birdied No. 3 to get some momentum.
'I hit the ball really solid, had a lot of good looks at birdie. Made some good ones, missed a couple of very easy putts,' Creamer said. 'But overall, it's the first day and I am very pleased with the way I played.'
Creamer finished second to Annika Sorenstam in the 2005 tournament, and was fifth last year when Lorena Ochoa won.
Ochoa led most of the first round this time, but a late lapse cost her when she made a double bogey on the final hole to drop into a three-way tie with Morgan Pressel and Mi Hyun Kim at 68.
Wie, who turned 18 on Thursday, sprayed some shots and couldn't get putts to fall. She was three shots behind 19th-place Bettina Huart.
'It was a really tough day for me,' Wie said. 'I just couldn't get anything going. What really was the pinnacle of the day: I hit a really good wedge shot and it hit the pin and came back 30 feet. It was just that kind of day.'
She still managed to par that hole.
'All the putts looked like they were going to go in, but they didn't,' Wie said. 'Obviously, I had a couple of stray tee shots. But there's always tomorrow.'
Asked what she was doing for her birthday, Wie, a Stanford freshman, said, 'Go home and study. Basically, I have a lot of stuff to do. I have to read a book, so it should be an exciting birthday.'
Wie has struggled this year, making only two cuts and earning a total of $9,899 in seven events. She had been hampered by a wrist injury, but said it was much better this week.
With conditions ideal on a sunny, still day in the desert, half the field in the elite event finished the first 18 holes under par at Big Horn Golf Club.
Ochoa didn't have a bogey until she ran into trouble on the final hole. She hit her tee shot far to the right and the ball lodged in the top of a bush. She took an unplayable lie, then hit her next shot into a bad lie in the rough.
The 2006 player of the year, Ochoa has won six times this year, including the Women's British Open for her first major victory. She tops the money list with a tour-record $3,068,421.