For Sarah Burnham, the considerable difference playing on the LPGA Tour as a professional compared to being an amateur is magnified in majors.

The Maple Grove native will put her experience as a three-year pro to the test at the U.S. Women's Open, held Thursday through Sunday at The Olympic Club in San Francisco.

"I am used to everything now," Burnham said. "It's still not easy playing on the LPGA Tour, but when I am playing well it is really nice."

Burnham will be joined at the Open by fellow Minnesotan and amateur Isabella McCauley, who will become the youngest girl in state history to play in the event. The 17-year-old Simley junior finished second to Burnham in an Open sectional qualifying tournament to make the field of 156 golfers.

"I am really happy for her," Burnham said. "It's nice to see great players coming out of Minnesota."

Burnham will be playing in her second Open. Her first was as an amateur after her freshman season at Michigan State in 2015.

"It was a once-in-a-lifetime experience that I will never forget," said Burnham, who had won the Class 3A individual state championship at Wayzata two years earlier. "I was extremely nervous."

A large part of that was due to the crowd. The two-time Big Ten Player of the Year with the Spartans didn't have much fanfare at the collegiate level.

"I wasn't used to playing before fans," Burnham said. "The crowd is all cheering for the amateurs, too. It was overwhelming."

Burnham shot a 9-over-par 79 in her opening round at Lancaster Country Club in Pennsylvania. The next day she had a 74 and missed the cut.

"I don't even know how I made it six years ago," Burnham said. "I've completely changed my game since then. Every year I have gotten a little better, little smarter."

She tied for sixth place — a career-best finish — last season at the Drive On Championship at the Inverness Club in Toledo, Ohio. Her best finish this season, tied for 27th, came in the Hugel-Air Premia LA Open in April.

"Every little thing can make a big difference on the Tour," Burnham said. "I'm always trying to figure out how I could have saved two or three shots every round."

Both Burnham and McCauley are small compared to other players on the circuit. Burnham is 5-4, two inches taller than McCauley.

"My distance off the tee is something I will always be working on," said McCauley, who won the 2019 Class 3A individual state championship with a record-tying total of 9-under-par 135.

McCauley averages 240 yards off the tee while Burnham's average driving distance is 256 yards.

"Consistency is my strength," McCauley said. She edged Lindy Duncan, who has earned more than $1 million on the LPGA Tour, by one shot for the final spot in the qualifying tournament.

"I don't miss a lot of fairways/greens in regulation," McCauley said.