The National Park Service is investigating the discovery of human remains in the western part of Yellowstone National Park last week, a park spokeswoman said Thursday.

Visitors snowshoeing within park boundaries but near West Yellowstone, Mont., came across partial remains of an individual in the snow on March 2, Amy Bartlett said.

"The following day, some park rangers and volunteers that went out with a cadaver dog team, and found more remains," Bartlett said. "The remains have been heavily scavenged by animals, however, there is no evidence that this death was the result of any sort of animal attack."

Evidence at the scene suggests the individual died within the park sometime in January.

There are no signs of foul play.

The National Park Service is working with the Montana Crime Lab to determine the identity of the individual.

As of Thursday, there is no indication of the individual's sex or age, Bartlett said. She did not know if there were any personal effects found with the remains, she added.

The park did not plan to issue a news release until investigators knew more, Bartlett said. "But people in West Yellowstone were getting worried that maybe it was something more drastic than what it reality it probably is. We were just trying to quell the rumor mill that might be happening."