During a steamy July week in the North Carolina Sandhills, retired Dartmouth golf coach Bill Johnson became reacquainted with Peter Williamson, the three-time Ivy League golf champion.

The last time Johnson had seen him, Williamson was a slight, determined kid participating in the longtime Big Green mentor’s junior golf program at Hanover Country Club. More than a decade hence, the tall and lean college grad was among the elite golfers at the prestigious North & South Amateur Championship at Pinehurst Resort, a venerable retreat in the heart of perhaps America’s foremost golfing mecca.

A resident of nearby Southern Pines, Johnson watched as Williamson competed primarily against golfers who had honed their swings in the Sun Belt, not ski country. With the mercury rising mercilessly above 100 degrees for three days, Williamson shot the best 54-hole qualifying score among 132 entrants. And while most of his fellow competitors wore shorts in the heat, Williamson sported trousers.

Impressed with Williamson’s game, Johnson was also curious about his wardrobe choice. “I asked him about the slacks,” the former coach explains, “and he said, ‘Well, they don’t wear shorts on tour.’ ”

That would be the PGA Tour, the world’s leading professional tournament circuit on which famous players such as Tiger Woods and Phil Mickelson compete for trophies—and millions. The players don’t wear shorts, per tour rules.

Eschewing shorts on the golf course has been Williamson’s habit for as long as his father, Doug ’85, DMS’93, can remember. In fact, Doug says, his son probably doesn’t even own a pair. Call it premature, but Williamson’s adoption of the PGA Tour’s standard uniform speaks to his single-minded focus on reaching the game’s most prominent stage.

In four years at Dartmouth, Williamson established himself as one of best golfers in Ivy League history, becoming only the second player to win three individual league titles. With a memorable summer the Hanover native proved that he could compete favorably with the nation’s top amateur players.

In match play at the North & South Amateur, Williamson defeated four opponents on Pinehurst’s No. 2 course to win the title. Two weeks later he captured the Southern Amateur in Little Rock, Arkansas, and in early August he advanced to the semifinals of the Western Amateur in Chicago. Although his summer ended in disappointment—with his dad as caddie, Williamson lost to the world’s top-ranked amateur, Chris Williams, 3 and 2, in the first round of match play at the U.S. Amateur Championship at Cherry Hills Country Club outside Denver—his summer showing turned heads.

“When you hear about a kid growing up in New Hampshire and playing at an Ivy League school you expect him to be an intelligent golfer out there, but not necessarily hold up on the talent level,” says Ryan Herrington, a senior writer for Golf World magazine who watched Williamson at the U.S. Amateur. “But he definitely holds up on that end as well.”

For Williamson, his summer performance “validates the fact that I’ve been doing the right thing,” he says. “I wanted to put a premium on academics and work on my athletics as well, and I knew when I got out of college I was going to give [pro golf] a shot, because it was worth it. I think these tournament victories help me believe that it was the right decision.”

As his classmates launch careers in professions such as medicine, law or finance, Williamson is chasing his dream. In early September he moved to Florida to begin preparing for the PGA Tour Qualifying Tournament, better known as Q-School in golf circles. In mid-October he was slated to tee off in the first of the Q-School’s three main qualifying stages, which will culminate in early December with 25 golfers earning PGA Tour playing privileges for 2013.

Because his Southern Amateur victory earned him an invitation to play in the tour’s Arnold Palmer Invitational in Orlando, Florida, next March—an offer contingent upon him competing as an amateur—Williamson planned to enter Q-School as an amateur, thereby preserving the option to make his tour debut should he fail to advance through the Q-School’s early stages. Should Williamson’s Q-School performance earn him playing privileges on either the PGA Tour or its feeder circuit, the Web.com Tour, he would almost certainly turn professional before year’s end, he says.

Williamson’s golf journey began at age 2, when his maternal grandmother, Sandy Glah, gave him his first club. He started playing Hanover Country Club with his father at 7, was beating him by 12 and at 15 qualified for his first national tournament, the U.S. Junior Amateur in Rancho Santa Fe, California.

Although Williamson took pointers from his father and attended Johnson’s junior clinics, he never took formal lessons. Instead, he emulated the pros he watched on TV and practiced tirelessly. Despite leading Hanover High School to four state golf titles, however, Williamson received no scholarship offers. He considered walking on at the University of Michigan, Boston College or Cal Poly San Luis Obispo before enrolling at the alma mater of not only his father but his grandfather, Peter ’58, and great-grandfather, Norris ’26.

Williamson became Dartmouth’s No. 1 player as a freshman, thanks largely to a work ethic former teammate Davis Mullany ’11 observed on the team’s spring trip to the Dominican Republic that year. “Pete would skip his lunch break to keep practicing,” Mullany says. “He wouldn’t eat at all, just to get an extra 45 minutes or an hour out of his day. I think that dedication has gone a long way for him.”

Known for a few-times-a-week winter ritual of stroking 800 consecutive practice putts on his dorm-room carpet, Williamson says he spent one to three hours a day practicing in his dorm room. “I took Chinese freshman year, so the memorization assignments allowed for simultaneous putting drills,” he says. “I tried to be as efficient as possible.”

Williamson won Ivy League titles as a freshman, junior and senior and earned conference player of the year accolades in each of those campaigns. As a senior he posted an NCAA-low 69.88 scoring average and nearly led Dartmouth to its first Ivy League team title since 1983. (The team finished second, losing in a heartbreaking playoff to Penn.)

Williamson’s example rubbed off on his teammates, says coach Rich Parker. “We lose in a playoff for the Ivy League Championship on a Sunday and get home at 3 o’clock in the morning from the tournament,” he explains. “I go to the course Monday, and all my kids are playing golf. The season’s over. That would never happen years ago.”

For all the glory and riches professional golf offers top players, the odds of making it are long. In Williamson’s case they are probably longer, given that no Dartmouth golfer or New Hampshire-bred player has ever competed full time on the PGA Tour. But Williamson is confident he can succeed.

“I feel like my mental game is what’s going to get me there,” he says. “I feel like I can get my game in shape with a 12-month golf season, so I don’t have that rust on the bookends of the season. With all the preparation and dedication that I have to this game, I feel I can compete with anyone.”

Upon moving to Florida Williamson was primed to test his game against the best on a daily basis at the Medalist Golf Club, an enclave north of West Palm Beach that counts several tour players, including Tiger Woods, as members. Through Parker, Williamson met Medalist member Olin Browne, a longtime PGA Tour player who once played in golf’s minor leagues with the Dartmouth coach. Thanks in part to Browne, Williamson received an invitation to join the club as a junior member. He has finally replaced his rickety team bag with one emblazoned with an embroidered Dartmouth logo on its front pocket.

“Peter’s going to be exposed to some of the best and the brightest,” Browne says. “If you are in that kind of an environment, it’ll have a big impact.”

Williamson plans to devote at least five or six years to becoming the best golfer he can be, he says. And if that’s not good enough to yield PGA Tour success, he’ll try something else. Williamson earned his degree in studio art with an architecture concentration and a geography minor, a course of study he envisioned as groundwork for a possible golf course architecture career, he says.

Even with that preparation, Williamson should not let the notion he’d put his degree to better use in a more traditional profession interfere with his aspirations, says Bob Heintz, the Yale ’92 golfer whose record of three Ivy League titles Williamson equaled. “Just because you went to Dartmouth or Yale doesn’t mean that there’s some restriction about whether you’re going to choose to be a professional athlete,” says Heintz, a veteran pro who played five seasons on the PGA Tour and still competes occasionally on the Web.com Tour. “He’s very good at it, and a lot of people would like to see him do it. And if he enjoys it, he’s earned the right to pursue it.”

Mike Cullity is a freelance journalist and a reporter for the New Hampshire Union Leader. A 12-handicapper, he lives in Manchester, New Hampshire.