The 2011 U.S. Open is in full swing now, and an American is atop the U.S. Open leaderboard early on in Thursday's action. Ryan Palmer, a 34-year old from Texas, is off to a fast start, with three birdies in his first 10 holes to go into sole possession of first place at three-under par. 

A group of three is right behind Palmer at two under, including Chez Reavie, Johan Edfors and Jeff Overton. A host of others sit back at one-under, including defending champion Graeme McDowell. Here is an updated leaderboard.

1. Ryan Palmer: -3 through 10
2. Chez Reavie: -2 through 16
3. Johan Edfors: -2 through 11
4. Jeff Overton: -2 through 10
5. Graeme McDowell: -1 through 13
6. Y.E. Yang: -1 through 12
7. Jason Day: -1 through 10
8. J.J Henry: -1 through 10
9. Davis Love III: -1 through 11
10. Brandt Jobe: -1 through 10
11. Christo Greyling: -1 through 9
12. Bud Cauley: -1 through 7