Wie, the winner in Hawaii in April, birdied three of the last four holes in her morning round. She's seeking her second victory in Canada after winning the 2010 Canadian Women's Open in Winnipeg, Manitoba.
''I was consistent and I felt that I judged the wind pretty well today,'' Wie said. ''Tuesday's practice round was a lot windier, so I think that was very helpful.''
She was asked if it was the strongest wind she had faced in a tournament the last couple of years.
''Yeah, for sure,'' Wie said.
Park had a bogey-free round in the afternoon.
''Today, bit lucky,'' Park said. ''Still three more rounds left, so going to keep staying patient.''
Last year, the South Korean player beat Angela Stanford on the third playoff hole after they finished at 26-under 258 to match the tour record for lowest total score.
''I was early off and I just wanted to make a lot of birdies early on,'' Wie said. ''And just especially 26 under winning this last year, it's definitely one of those golf courses where you have to keep making birdies. My 6 under today, you know, it's not enough. I need to keep making birdies for the rest of the weekend. Still a lot of work cut out for me.''
China's Shanshan Feng was a stroke back, and countrywoman Xi Yu Lin matched Cristie Kerr with a 67.
''Nice to be out of the wind,'' Kerr said after her round.
Stacy Lewis had a 69 in her first round since taking the top spot in the world with a victory Sunday in New Jersey. Second-ranked Inbee Park also shot 69, and No. 3 Lydia Ko had a 71.
Brooke Henderson, the 16-year-old Canadian who is third in the world amateur ranking, had a 70. She had a birdie and three bogeys on the front nine to make the turn in 2 over, then birdies Nos. 14, 17 and 18.
''It was a rough start, but a good finish really saved my round,'' said Henderson, from Smith Falls. ''One-under par in this wind on the first day, I'll definitely take it. ... It's tough with all the wind out there. It's strong and you have to be really careful in club selection.''