The tourist was visiting the partially reopened park when she got too close to the animal. This incident was the first reported bison attack of the year.
The woman was "knocked to the ground and injured by a bison in the Old Faithful Upper Geyser Basin after approaching the animal too closely," park officials told the newspaper.
The National Park Service requests tourists maintain a distance of at least 25 feet from all animals.
It was reported that the woman's injuries were medically "assessed" at the park and that she refused further medical attention when offered. The exact extent of the woman's injuries remained unclear and the incident is currently under investigation by the National Park Service.
Yellowstone National Park reopened to the public on Monday after being shut down since late March to help stop the spread of coronavirus. The park had initially announced a phased opening that would start on May 18, however, those plans were pushed forward after President Donald Trump announced earlier this month that all national parks would open "rapidly."
The original phased plan included "reopening access to two of the park's five entrances and allowing visitors to sightsee in the lower loop of the park," the New York Daily News reported.
Yellowstone National Park spans three different states -- Montana, Wyoming, and Idaho. Wyoming has lifted their travel ban, but the others -- where most of the entrances are -- have not. Those gates will not be able to be used until after the restrictions are lifted.
This incident is not the first injury at Yellowstone this year, however. On May 12, a different unidentified woman illegally entered the park and suffered burns after she fell into a thermal feature while attempting to take a photo. She was able to drive herself 50 miles until a park ranger pulled her over and saw the extent of her injuries. She was airlifted to a local hospital where she received treatment. Her current condition is unknown.
Earlier this year, the park's bison were culled and slaughtered in an attempt to lessen the number of animals living there. An estimated 4,900 bison called Yellowstone home earlier this year. Park officials hoped to reduce that by 900, since the land does not provide enough food for that many animals.