Last time the U.S. Open was at Oakmont in 2007, 5 over par won the tournament. Angel Cabrera squeezed out Jim Furyk and Tiger Woods by one stroke each to take home the victory. Cabrera was the only player to break par twice, mostly on account of the penal greens which might be some of the toughest in the country.

"If Oakmont has a signature, it has to be these lightning fast greens," USGA Executive Director Mike Davis said earlier this year. "And this isn't a recent phenomenon. These greens have been like this really from day one. In fact, if you go back [to] the 1935 U.S. Open that was played here, the players were complaining incessantly about the greens being too fast. That was 1935. In fact, some of them almost boycotted and didn't want to play."

Justin Thomas recently took a recon mission up to Oakmont with his vacation buddies Smylie Kaufman and Rickie Fowler. He reported back to Chris Solomon of No Laying Up.

"They're so hard, they really are," Thomas told NLU. "It depends on how it's set up. It could be a total complete survival week. I can't imagine a setup where under par wins. It's just a hard course. It's a great U.S. Open course. You're going to see some serious numbers put up. I hope I'm not one of them."

He went on to say that Adam Scott reminded him at this year's Players Championship that in 2007 when he played at Oakmont, he hit six of 36 greens. (Six! Adam Scott!)

"I started laughing," said Thomas. "I was like, 'I'm sorry, I'm not laughing at you, but I've never heard of someone who hits it as good as you do hitting six greens.'"

The other spring break buddy weighed in before The Players after his own trip up to Oakmont.

"There's just so many other tough holes that par is going to be a fantastic score," Spieth said. "I'd sign for even par right now for 72 holes in June. Obviously given the history, but also having played it."

The USGA seems to be intent on making them as smooth and as fast as possible. As Golf Digest recently noted:

"In the last two growing seasons, the putting greens at Oakmont Country Club have been double drilled-and-filled four times, core aerated five times, deep verticut five times and deep-tine aerated four times," Darin Bevard, director of championship agronomy for the USGA wrote. "The aeration programs implemented at Oakmont Country Club are very aggressive and represent a significant disruption to playability that most golfers would not tolerate." And during the Open, the greens "will be mowed four times and rolled twice daily."

So enjoy the low scoring over the next few weeks while you still can because Oakmont is going to be a reminder of just how difficult golf can be.

Justin Thomas gets a feel for the greens. USATSI