Natalie Gulbis, Sherri Turner and Tina Barrett all posted rounds of 6-under- par 66 and are tied for second place.
Karrie Webb, Pat Hurst, Dina Ammaccapane, Rachel Hetherington, Vikki Laing and Jenna Daniels are knotted in fifth place after opening with rounds of 5-under-par 67.
Bowie began with three pars on Thursday, then broke into red figures in a big way at the par-5 fourth. She chipped in for eagle from 15 yards off the green, but parred her next four holes.
She started a run of strong golf at the ninth when she knocked a pitching- wedge to six feet and converted the birdie putt. Bowie collected her second birdie in as many holes at 10 when she once again used a pitching-wedge, but this time her ball stopped eight feet from the stick. She completed three birdies in a row with a 12-footer at the 11th.
Bowie parred holes 12-14, but bounced back at the par-5 15th. She played a 3-wood on the green with her second, then two-putted for birdie to reach 6-under for the round.
The 30-year-old moved ahead of the pack at the 18th. Bowie hit a pitching wedge to four feet to set up her fifth birdie of the round and sole possession of the lead.
'My round was just steady today,' said Bowie, who earned her first win a playoff at this year's Jamie Farr Owens Corning Classic. 'I hit every green and gave myself a lot of chances.'
Bowie might have something to prove this week. After last week's Wendy's Championship for Children, United States Solheim Cup captain Nancy Lopez picked Beth Daniel and Wendy Ward for the team. Bowie finished 12th in points and was passed over.
'I don't feel like I have a point to prove,' admitted Bowie, who went 0-3 in her only Solheim Cup experience two years ago. 'I was disappointed. There are 12 people on the team and I was 12th in points, so over two years if you look at the points, I was certainly good enough to play on the team.'
Gulbis, who made her first Solheim Cup for the American side, began on the back nine Thursday and collected birdies at the 12th and 15th holes. She continued to play well around the turn when she birdied the first, but Gulbis moved up the leaderboard thanks to her play at No. 4.
Gulbis eagled the par-5 hole to reach 5-under par for the championship. She added another birdie at the par-three seventh to get into the logjam in second.
Turner, who won the LPGA Championship in 1988, flew out of the gate on Thursday. She parred the first, then birdied five in a row from the second. Turner birdied No. 9 to make the turn in 6-under-par 30.
On the back nine, Turner birdied the 13th to join Bowie atop the leaderboard at 7-under par. She dropped a shot at the par-3 16th to fall back into second.
Barrett had a much more up-and-down round than anyone else near the top of the leaderboard. She began on the back nine at The Rail Golf Course and bogeyed the 11th. She rebounded with back-to-back birdies from the 12th and four in a row from No. 17.
She bogeyed the third, but birdied the remaining par-3s, five and seven, to get within one of the lead.
Defending champion Cristie Kerr is part of a group tied for 11th at minus- four.