Christie Kerr, the winner in 2008 the last time the event was played at Columbia Edgewater, was at 66 along with Lizette Salas and Germany's Sandra Gal.
Second-ranked Stacy Lewis, returning to play after withdrawing from the Canadian Women's Open last week because of illness, opened with a 67. She won the Women's British Open on Aug. 4 at St. Andrews and had consecutive early season victories in Singapore and Phoenix.
Hall of Famers Juli Inkster and Se Ri Pak also were in the large group at 67 that included Michelle Wie, Yani Tseng and Ai Miyazato. The 53-year-old Inkster won the last of her 31 tour titles in 2006.
Suzann Pettersen, the 2011 winner, also shot 68.
Defending champion Mika Miyazato opened with a 71
Tiger says back is fine, he's ready to go
Tiger Woods planned to take it easy during the pro-am at the Deutsche Bank Championship in Norton, Mass. His back felt so good he decided to play all 18 holes.
Woods hit a variety of full shots with no indication of any pain. It was far different from four days ago, when he dropped to his knees after a back spasm when he hit one errant shot in The Barclays.
The Deutsche Bank Championship starts Friday, and Woods say the extra day off for treatment and rest has helped.
The Deutsche Bank Championship is the second playoff event for the FedEx Cup. Woods remains No. 1 in the standings, narrowly ahead of Scott with Phil Mickelson at No. 3. Those three players will be in the featured group the opening two rounds of the tournament that starts Friday for its traditional Labor Day finish.
"The back has been ... it's a lot better than obviously on Sunday," Woods said. "It was nice to have that extra day of rest. Having the tournament start on Friday certainly helps. And I've gotten treatment every day, two to three times a day. And it feels good."
It was the third time this year Woods has shown physical discomfort on golf course. An elbow injury forced him to miss two tournaments in the early summer. He was grabbing his lower back in the final round of the PGA Championship. And then at The Barclays last week, after complaining of a stiff lower back from sleeping on a soft mattress in his hotel, Woods fell to his knees on the 13th hole after what he said was a back spasm on his second shot to a par 5.
His health figures to be a talking point at the Deutsche Bank Championship, at least until he gets to the 10th tree Friday morning to begin the tournament in the ultimate power grouping Woods, British Open champion Phil Mickelson and Masters champion Adam Scott, who not only are Nos. 1-2-3 in the FedEx Cup, but 1-2-3 in the world.
Even before he could hit his first tee shot in the pro-am, one of the amateurs asked him about his back.
The question was inevitable. The answer was predictable.
"It's fine," Woods said.
The rest of the round was just like any other. There was no indication of injury, plenty of laughs and even the occasional, "Good shot, Mike," from Woods. He was speaking to New York City Mayor Michael Bloomberg, one of his amateur partners.