The Georgia State Patrol says Hoppenbrouwer was driving 18 Masters patrons Thursday from Atlanta to Augusta when the bus left the road, spun and overturned on Interstate 20.
The Masters is one of pro golf's four major tournaments, and it draws fans from around the Southeast - and around the world.
Police say Hoppenbrouwer ran the side of the trail and over corrected until the bus overturned to the median. The driver, 61-year-old Steven F. Hoppenbrouwer, was charged with driving under the influence.
Nine people are being treated at Doctors Hospital in Augusta.
The Augusta Chronicle reported that seven adult passengers were transported to Augusta University Medical Center, a Level 1 trauma center.
Doctors Hospital in Augusta also said an additional seven people were being treated at their facility.
Passenger Kip Plowman said the first time the bus swerved, the driver said he turned to avoid "a tire or a piece of metal in the road".
"We know that there are multiple injuries", Columbia County sheriff's Lt. John Sherman said. 18 people were onboard the bus at the time of the crash.
The bus, which was carrying a group from Atlanta to the tournament, is owned by Jet Executive Limousine, troopers said.
A person who answered the phone at the business declined to comment, saying the company was "in the dark" about the details of what happened.
The crash originally led to the closure of lanes on both sides of the interstate.