UPDATES: From 2.9: The shutdown is over, for now. The government is funded through March 23rd, we'll keep this page going as we may yet have a need for this info in case a long term funding deal isn't reached by then.
1. Most National Park Service lands will remain open but unstaffed. Any portion that requires services (campgrounds, visitor centers, bathrooms, EMS/Fire, etc) will be closed. Risky, dangerous, and sensitive areas will also be closed. If any portion of a park (including the full park, in some cases) is shut and locked during off-business hours, it will be closed during the shutdown. NPS campgrounds are a different matter with this being the official word from the Department of the Interior "The NPS will cease providing services for NPS operated campgrounds, including maintenance, janitorial, bathrooms, showers, check-in/check-out and reservations. Visitors in campgrounds will not be asked to leave but should be advised that no services will be available. In addition, visitors holding campground reservations for a later date will be advised that the NPS is not operating campgrounds, including providing check-in/check-out s ervices during a shutdown. There is no guarantee their reserved campsite will be ready and available should they arrive during a government shutdown"
2. NPS employees will be on furlough, with no access to phones, websites, or social media accounts.
3. The fate of recreation.gov is clear, it is now down and not accessible for new reservations or modification of existing reservations. Anyone who has a reservation that falls within the shutdown calendar will receive a full refund. Other NPS sites, such as NPS.gov, the individual parks sites and other federal public lands websites (like Fish & Wildlife) remain online but clearly, they will not be updated as the employees are on furlough.
4. No new backcountry permits will be issued.
5. Open air monuments, like the World War Two Memorial, will remain accessible to the public though they will not be staffed.
6. National Wildlife Refuges look to stay open, but with no services (visitor centers, bathrooms, EMS/Fire, etc) Refuges that allow overnight camping and boon-docking, appear at this point, to require those campers to leave with two days notice, in theory 12:01 AM Monday.
7. National Forest facilities will be closed. Campsites are closed. All campers must leave with two days notice. Major roads that run through National Forests will remain open, though services such as snow removal will cease.
8. While the possibility is highly remote, as nearly all federal employees are furloughed, you could be subject to possible law enforcement action if found on closed federal land.
9. State and local parks will remain open! There are some great options out there, explore more and find your park.