Story highlights The mother of the girl says she shot herself with a handgun

The incident is under investigation

Rangers at Yellowstone National Park are investigating the shooting death of a 3-year-old girl at a campground inside the park.

The mother of the girl told a 911 dispatcher that the girl shot herself with a handgun Saturday morning, according to a statement from the park.

The girl has been identified as Ella Marie Tucker from Pocatello, Idaho.

Visitors to the park are legally allowed to carry guns, but "discharging a firearm for any reason is illegal," according to the park.

Park rangers and special agents are investigating the circumstances surrounding the shooting.