A DNR helicopter pilot and two civilians were killed Thursday in an aerial attack near Yellowstone National Park, officials said.
The National Park Service said the crash was caused by a single-engine plane.
It was not immediately clear whether the helicopter pilot was on board.
The helicopter was in the area near the South Fork River and the South Summit Trail.
The crash was first reported at 9:55 a.m.
(8:55 p.m.) by a park ranger.
It continued for about 30 minutes before it crashed, the park service said.
No injuries were reported.
The plane was part of a special operations team that has been in the Yellowstone area since January.
The mission is to support a major firefighting effort, said Chris Burt, an agency spokesman.
The DNR said in a statement that the helicopter was operating from an area in which a large fire is burning.
The park service and National Park Fire Authority were conducting an investigation.
The plane crash is not the first time a DNR plane has been shot down in the wild.
In 2013, a helicopter pilot died in a fire near Yellowstone.
The pilot was operating a firefighting helicopter that had been outfitted with a GPS system.
The fire burned for more than a week and destroyed a large portion of the town of Pawnee, about 30 miles (50 kilometers) north of Yellowstone.
A small part of Paw Paw Hill National Park is in the fire’s vicinity.