If the United States government shuts down at midnight, Friday, April 8, because Congress has been unable to pass a budget, national parks will shut down according to previous precedents. Since nobody expected it to go this far, there has not been a lot of formal announcements on what would happen. But now as it gets closer you can be assured it will affect highpoints in National Forests and National Parks with National Parks being the most obvious since the whole park could be shutdown (e.g., Clingmans Dome, Rainier, Whitney, Denali). You should plan ahead. Unfortunately the closures may not be posted because the government will shut down.
We have heard specifically that the Great Smoky National Park will close the road going through it including access to Clingmans Dome which just opened for the season.