Sylvan Pass

All oversnow travel will end for the season at 9 p.m. Thursday, March 15.

The map on the website, in addition to phone recordings, will be updated as conditions change.

Park officials will closely monitor avalanche conditions and additional closures may occur.

The road over Sylvan Pass east of the east entrance of Yellowstone National Park reopened Friday evening after the discovery earlier that day of an unexploded device used for avalanche control, a park spokeswoman said.

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.

Only three of more than 100 howitzer shells launched to trigger avalanches failed to explode this winter on Yellowstone National Park's Sylvan Pass.

Warmer Temps + Melting Snow = Park-wide Challenges. Sylvan Pass Slides Delay East Entrance Reopening.