A Yellowstone National Park visitor was gored this week as she tried to snap a selfie close to one of the park's famed bison, the fifth attack on a tourist, who has ignored warnings to admire the mammals from afar, officials said on Thursday.

The 43-year-old Mississippi woman and her daughter were standing with their back to a bison when it charged on Tuesday, tossing her into the air and inflicting minor injuries, Yellowstone spokeswoman Amy Bartlett said.

She was the fifth Yellowstone visitor since May to be gored by one of the park's popular bison, which can weigh as much as a ton, and the third tourist seeking to take a picture of a buffalo while crowding too close.

The millions of tourists who visit the park annually are warned when they enter Yellowstone, by handouts, signs and orally to keep a distance of at least 25 metres from bison and to give even more berth to creatures such as grizzly bears, said Ms. Bartlett.

Yet the message is clearly not getting through to some individuals who flock to a park that spans more than 8,800 sq km of Wyoming, Montana and Idaho.