Polygon has learned that a federal investigation into a man’s death at a wolf waterhole in Montana last year has been closed, but the investigation is still active.
According to the Montana Department of Health and Environment, a person at the Wolf Waterhole, located in the town of Wolf Springs, died of an apparent drowning in late July 2016.
Investigators say the cause of death is undetermined, but they have not ruled out foul play.
The incident is one of a handful of deaths at the area since 2016.
A second man, who is still unidentified, also died there.
Wolf Springs has been designated as a wilderness area in Montana by the federal government.
That designation means that anyone who enters the area may be subject to additional restrictions.
The U.S. Forest Service requires that visitors to the area must be at least 21 years old, wear a life jacket and carry a life vest.