The first round of the 2012 U.S. Open at the Olympic Club in San Francisco is well underway on Thursday. A couple of the marquee players are already through their first nine holes and, so far, the course is looking to play every bit as difficult as anticipated.

After bogeying his first three holes after starting the day on the ninth tee, Phil Mickelson is currently sitting at 4-over, with five bogeys and a birdie through his first nine holes.

Odds-on favorite to win Tiger Woods is also through his first nine holes and is at even par thus far. After also starting on the ninth tee, Woods shot a bogey on 14 and birdied on 17.

The current leader is Branden Grace of South Africa, at 3-uunder through his first 10 holes.

You can find a full 2012 U.S. Open leaderboard at Golf.com.

For all your news and updates in the run up to the 2012 U.S. Open at Olympic, visit SB Nation's dedicated golf hub. Be sure to head over to USOpen.com for even more coverage from the event.