15-year-old Cole Hammer during the first round of the 2015 U.S. Open Championship at Chambers Bay, Washington.Ross Kinnaird/Getty Images
The year's second golf major attracted a large crowd Thursday.Mike Ehrmann/Getty Images
Dustin Johnson looks for his ball after a stray tee shot at the 10th hole but would recover to lead during early morning play.Ezra Shaw/Getty Images
Phil Mickelson was one of the first players on the course at the U.S. Open Thursday and started strongly before fading as his round progressed.Harry How/Getty Images
Another player to make a strong start was Patrick Reed, spotted here relaxing against his putter.Mike Ehrmann/Gety Images
Germany's Martin Kaymer was looking to defend the title he won in 2104.Ezra Shaw/Getty Images
Tiger Woods was a late starter at Chambers Bay Thursday.Ross Kinnaird/Getty Images
Rory McIlroy plays out of the bunker on the 18th hole at the Chambers Bay course. The Northern Irishman would finish the day with a two-over-par 72.Ross Kinnaird/Getty Images