Let's be real: keeping a National Park and other public lands open and running smoothly is a logistical miracle.
In Yosemite, two campgrounds and a popular redwood grove have closed for public safety reasons in the south of the park after human feces and urine created a health hazard, a spokesperson told the LA Times.
Handwritten signs have also been posted asking visitors not to litter, as there are now no trash services.
The failure to pass a federal government funding bill has left 800,000 employees without pay and left parks, national monuments, museums and zoos relying on a skeleton staff and volunteers. It is unclear how long the shutdown will last and whether the National Park Service will opt to close some or all of the parks if the situation continues.
"The park is being forced to take this action for health and safety concerns as vault toilets reach capacity", the National Park Service (NPS) announced. Other visitors and a park ranger reportedly helped 26-year-old Joshua Snider after he broke his leg while hiking in Big Bend National Park in Texas on Christmas Eve.
Even more seriously affected is the Mexican town of Boquillas, which is just across the Rio Grande from the national park and has always enjoyed a stream of visitors this time of year.
But for other national parks, its a different story.
"I made a decision to clean up this one section, because that's what Americans will do", said Snake, a 64-year-old member of the indigenous Ho-Chunk Nation in Wisconsin.
Park Service officials said the entrances to Great Falls Park in both Maryland and Virginia would remain closed to vehicles during the remainder of the shutdown, but people would still be allowed to walk in. "A nightmare scenario", he says.
There's been at least one reported incident of an injury in a national park during the shutdown.
British holidaymakers visiting National Parks in the United States have been warned to check before they travel as the United States government shutdown continues to cause significant disruption and environmental damage to a number of tourist destinations. "I would rather they close than be damaged", said Joe De Luca, a sales associate at Nomad Ventures in the town of Joshua Tree.
Joshua Tree Superintendent David Smith, in a statement, thanked the "local businesses, volunteer groups, and tribal members" who have stepped up to collect trash and maintain grounds during the shutdown.
Sequoia and Kings Canyon National Parks, twin parks in California's Sierra Nevada mountains, had to close a variety of sites as of 6 p.m. on Monday because of a trash overflow, USA Today reported Tuesday.