The discovery of unexploded ordnance has temporarily closed the road over Sylvan Pass to Pahaska which is east of the east entrance to Yellowstone National Park, according to a news release from park on Friday afternoon.

The ordnance is left over from avalanche hazard mitigation work.

The device was found this afternoon near the roadway of U.S. Highway 14/16/20.

The closure is expected to last a few hours while a team from Malmstrom Air Force Base in west-central Montana responds and destroys the device.

The park office does not expect to put out additional information on this closure unless conditions change dramatically.
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