Watch how Round 4 unfolded.
USGA representatives discussed why Johnson was penalized.
Controversy raged over whether Johnson should be penalized.
Dustin Johnson gets a free drop thanks to a TV tower.
Take a look at some vintage Oakmont.
Andrew Landry sits atop the leaderboard after Thursday.
Relive Jordan Spieth's 2015 U.S. Open win at Chambers Bay.
Watch this great shot by Matthew Fitzpatrick
The Pennsylvania venue hosting this year's U.S. Open has distinctive character.