Yellowstone National Park and Xanterra Parks & Resorts have released information about what will happen should the government shutdown occur tonight.
The short answer: the park will stay open, as will Xanterra facilities.
When the government last shut down in 2013, all facilities closed and people not staying overnight were asked to leave immediately; people staying overnight were given a few days to depart.
In the event of a government shutdown, according to the Bozeman Daily Chronicle, all National Park Service facilities (e.g. visitor centers) will close as early as Saturday morning. The majority of NPS staff will be required to stay home, although some will be allowed to continue working. From the Chronicle:
Heather Swift, a spokeswoman for the Department of the Interior, said in an email Friday that the department expects the government will remain open. But if it doesn’t, she said, national parks and other public lands “will remain as accessible as possible while still following all applicable laws and procedures.”
Snowplows will run and drivers will still have access to the road between Mammoth and Cooke City. Commercial snowmobile and snowcoach tours will continue, but [park spokeswoman Vicki] Regula said non-commercially guided snowmobile trips wouldn’t be allowed.
She also said areas could be closed off if they become dangerous, and that the park will have limited ability to respond to emergencies.
The Chronicle adds that approximately 3,300 NPS employees would continue working (with 777 in the Intermountain Region, which contains Yellowstone) while the rest (over 21,000) would be furloughed.
Xanterra Parks & Resorts announced on their website that, since the roads and gates would be maintained, all facilities would be “open for business as usual.”