Thanks to the restoration, which included the removal of more than 5,000 trees, Oakmont has regained its take-no-prisoners image. Of course, that's the image the late Henry C. Fownes sought when he designed his only golf course in 1903.

Fazio Golf Course Designers engineered Oakmont’s $2.5-million restoration, and builder McDonald & Sons did the physical work.

"He set out to make the hardest golf course in America, and I think he achieved what he wanted to do," Zimmers says.

Oakmont hired Fazio Golf Course Designers to engineer the restoration and builder McDonald & Sons to do the physical work. Zimmers and his staff assisted throughout.

The ambitious $2.5-million restoration, aided largely by the use of old photographs of Oakmont in its heyday, touched about every part of the course and included a new irrigation system.

"They wanted to put the course back to the original design that Mr. Fownes had," Zimmers says of Oakmont's 400 members. "They have the utmost respect for Mr. Fownes."

There were few, if any, trees on the course when Fownes designed it, but they accumulated over the next 90 years. Most of the trees were planted in the 1960s as part of a beautification program. But the course became so overgrown with trees that playability suffered and turf weakened because of poor air movement and shade.

Oakmont's grounds committee decided it was time to bring down the trees. Oakmont was designed as a links-style course, not a parkland course, they reasoned. Not surprisingly, the board's decision sparked controversy.

The tree-removal program eliminated more than 5,000 trees beginning in 1995. Much of the work was done away from the prying eyes of tree lovers.

The tree-removal program began in 1995 under the direction of Mark Kuhns, who spent nine years at Oakmont and is now director of grounds at Baltusrol Golf Club. Zimmers inherited the project upon his arrival in 1999. Most of the work was done in-house and in the winter so tree-sentimental members wouldn't witness the severed lumber toppling to the ground.

Zimmers has fielded question after question from media members about the trees, especially in light of the U.S. Open. People, whether from the golf media or not, want to know why so many trees had to be cut down. It was part of the restoration, Zimmers tells them. And because there are fewer trees, "the turf is healthier and therefore we use less pesticides and fertilizer," he also says.

Tim Moraghan, the United States Golf Association's director of championship agronomy, describes the finished tree-removal program as "mind blowing."

"If you had seen the course before 1995 and seen it today, your jaw would hit the ground," Moraghan says.

Oakmont's turf will benefit from the tree removal, says Moraghan, who supported the endeavor.

"Are we there to play golf on quality turfgrass, or are we there to take a walk in the park and look at the birds in the trees?" Moraghan asked. "It's hard to convince people in the environmental community that taking down trees is beneficial. But were not taking down trees in a national park. Were taking down trees on a golf course."

Fazio's Tom Marzolf was the architectural anchorman for the restoration. Marzolf's first order of business upon arriving in 1999 was lengthening Oakmont from the tees. More than 200 yards was added to the course, which now plays about 7,255 yards. A new par-3 tee on No. 8 will make the hole 290 yards for the U.S. Open.

Oakmont's existing bunkers were also restored, and 10 bunkers were rebuilt. Fownes designed Oakmont with 300 bunkers, but many were removed to cut back on overall maintenance. There are about 200 bunkers on the course now.

The project included the refurbishing of the church pews bunker, one of the most famous bunkers in golf. Over the years, the church pews bunker floor had accumulated so much sand that it had become raised. The floor was lowered and the bunker's bottom was rebuilt. Two additional pews were also added to each end of the bunker.

Oakmont’s refurbished ditches provide good drainage, making them functional hazards.

Oakmont's other hazards — its ditches — also were repaired. Oakmont has no water hazards, but the ditches act as functional hazards and provide good drainage on the course.

Oakmont's push-up greens, which hadn't been disturbed in 102 years, also needed renewal. They were restored to their original size. Oakmont also installed the XGD, or Existing Greens Drainage, on all of its greens. Developed by T.D.I. International, XGD is a subsurface drainage system that removes surface water more rapidly and lowers the water table in the green, thereby improving turf drainage.

Zimmers has worked closely with Moraghan on course setup for the U.S. Open. "Hard and fair" is how Zimmers describes how the course will play.

Oakmont is known for its fast greens, which members prefer to run at 13 feet consistently on the Stimpmeter. The USGA plans to slow them down for the U.S. Open.

Oakmont's members, who love a tough test of golf, will take pride in that, Moraghan says. "They'll be boasting, 'We have to slow down the greens for [the pros],' " Moraghan says.

Oakmont's members like to brag about their course. They have plenty to talk about considering that this year's U.S. Open marks the club's eighth national championship, more than any other establishment.

Usually, a course closes a few weeks before U.S. Open week so divots and ball marks can heal, and loose ends can be tied up. Oakmont's members are not giving up their course to the championship until a day before the first practice round.

"That tells you how passionate they are about their golf," Zimmers says.