Seventeen-year-old Kristen Gillman has had quite the summer vacation.

The Pan American Games in Canada and the Women's British Open in Scotland were among her stops. This week, Gillman looks to defend her title at the U.S. Women's Amateur in Portland, Oregon.

Gillman, of Austin, Texas, has been on a whirlwind tour since winning last year's Amateur at Nassau Country Club in Glen Cove, New York, with a 2-up victory over Canadian Brooke Mackenzie Henderson.

About to embark on her senior year in high school, the Alabama-bound Gillman will take on 155 other amateurs at the Portland Golf Club. The tournament opens with stroke play on Monday and Tuesday. The lowest 64 move on to match play with a 36-hole final round on Sunday.

Just last month, Gillman played in the U.S. Women's Open in Lancaster, Pennsylvania; competed for the United States Pan Am games in Toronto; then headed to the Women's British Open in Turnberry, Scotland. That was her fourth career LPGA event.

"You know you're in Scotland when you walk outside of the hotel and hear bagpipes," she posted to Twitter.

In an interview with the USGA.com, she said there are times when the fact that she's a champion still gives her pause.

"You don't think anything of it before you are about to tee off and then when they announce your name, they announce you as the 2014 U.S. Women's Amateur champion. I always get surprised every time I hear that," she said.

There are nine past USGA champions in the field, most notably is Ellen Port, the 2013 U.S. Women's Senior Amateur champion who also captained the 2014 champion U.S. Curtis Cup team.

Port, at 53, is the oldest player in the field; the youngest is Anne Chen, 14, of Sugar Land, Texas.

Others playing this week include women's British Open Amateur champion Celine Boutier of France, and 15-year-old Eun Jeong Song of South Korea, who won the U.S. Girls' Junior title last month in Oklahoma.

The course at Portland Golf Club is set up at 6,360 yards and par-72 for the event, which is in its 115th year. It is the sixth time that the tournament has been played in Oregon, but first time at the 100-year-old club in southwest Portland.

There were a record 1,303 entries, breaking the previous mark of 1,209 set last year. Sectional qualifying narrowed the field.