The 2018 Yellowstone winter season officially ends today, March 15, 2018.
The Old Faithful Visitor Center, Snow Lodge Geyser Grill, Bear Den Gift Shop, and Warming Yurt have closed for the season. All save for the warming yurt will reopen in April.
In addition, all roads save for the North-Northeast Entrance road will close at 9 p.m. tonight for spring plowing.
Yellowstone facilities and roads close every March in preparation for the summer season, which starts in late April and goes through to September/October. The peak time, of course, is June through August.
Roads will start reopening later in April. You can see the full list below:
• April 20: West Entrance to Madison, Mammoth to Old Faithful, Norris to Canyon.
• May 4: Sylvan Pass, Canyon to Lake.
• May 11: South Entrance to West Thumb, Lake to West Thumb, Craig Pass, Tower Junction to Tower Fall.
• May 25: Dunraven Pass and Beartooth Highway.
Facilities will start reopening with the roads, starting with the Canyon General Store April 20. You can see the full list of opening and closing dates here.