In the event there is a government shutdown tonight, visitors will be immediately asked to leave Yellowstone National Park, and those staying overnight will be asked to leave in the next few days.
The protocol for the National Park Service would handle a government shutdown and a Yellowstone shutdown is pretty clear and set forth in this document. Basically, over 21,000 NPS employees (out of 24,645) would be furloughed, and virtually all services in National Parks — save emergency and essential ones — would be shut down. That means the gates to the Parks would be closed, with visitors asked to leave immediately. Concessionaires would also be barred from registering new guests: those staying at Yellowstone campgrounds and in Old Faithful Inn, Mammoth Hotel and Old Faithful Snow Lodge — the only three hotels open in Yellowstone as of today — would be given two days to make alternative travel arrangements. From the NPS planning document:
Effective immediately upon a lapse in appropriations, the National Park Service will take all necessary steps to close and secure National Park facilities and grounds in order to suspend all activities except for those that are essential to respond to emergencies involving the safety of human life or the protection of property. Day use visitors will be instructed to leave the park immediately as part of Phase 1 closures. Visitors utilizing overnight concession accommodations and campgrounds will be notified to make alternate arrangements and depart the park as part of Phase 2. Wherever possible, park roads will be closed and access will be denied. National and regional offices and support centers will be closed and secured, except where they are needed to support excepted personnel. These steps will be enacted as quickly as possible while still ensuring visitor and employee safety as well as the integrity of park resources.
The shutdown process will take place in two phases. Phase 1 includes all activities to notify the public of the closure, secure government records and property, and begin winding down operations to essential activities only. Phase 1 will take place over a day and a half. Phase 2 will be initiated by the Director and includes the complete shutdown of all concession facilities and commercial visitor services. Overnight visitors will be given two days to make alternate arrangements and depart the parks. At the end of Phase 2 operations are expected to be at the minimum levels defined below. The entire closure process – both phases – will be completed within four days.
Now, a government shutdown is not a given: there is an afternoon Cabinet meeting to address the issue, and both the House and the Senate are expected to discuss avoiding a shutdown today. If there is a shutdown, it would happen at midnight tonight, which means the gates to Yellowstone and Grand Teton National Park would be closed for travel tomorrow.