Kim Hancock, of Santa Rosa, California, was attacked after she and others got within 10 yards of the bison while walking along a boardwalk at the Fountain Paint Pot in the park's Lower Geyer Basin, the National Park Service said in a press release.
Jake Frank, a spokesperson for Yellowstone National Park, warned even if a bison doesn't feel threatened by you, if you get close and it bumps you, that's going to hurt.
The bison reportedly became agitated when it crossed the boardwalk and charged the crowd, goring Hancock.
The bison left the area right after. Hancock was taken to a hospital with a hip injury and was in good condition.
Conflicts have raged for years over how many bison the park can sustain and methods used to keep the population contained.
This is the second instance of a bison attacking a Yellowstone visitor this year.
Earlier in the week, two women were injured by elk, one on Sunday and another on Tuesday.
Cameron Sholly, the Park Service director for the Midwest region, is said to be in consideration for Wenk's Yellowstone job. Because of the severity of her injuries she was flown to an Idaho trauma center. "Give animals space when they're near trails, boardwalks, parking lots, or in developed areas".
The Trump administration issued a stern reply to Yellowstone National Park superintendent Daniel Wenk, who had offered to retire next year in order to avoid a reassignment to Washington: Leave your post by August or retire now. At one point, officials say, some people were within 15 feet of the animal.
Rangers recommend park visitors stay at least 25 yards away from animals, and at least 100 yards away from bears and wolves.
Park officials not that it's very common for cow elk to aggressively defend newborn calves and hide them near buildings and cars.