National Parks employees have closed the last four miles of the road to Oregon's iconic Crater Lake, saying that the government shutdown is preventing them from emptying the park's toilets.  That could allow human excrement to overflow into the lake.

Crater Lake National Park announced the closure of the main road to the lake on Jan. 3, the 12th day of a government shutdown triggered by President Donald Trump's demand for a border wall.

"Due to conditions caused by the impact of human waste buildup on the park's water system, the road to Crater Lake is now closed to vehicles at Hwy. 62 in order to protect public health and park resources," park officials said in a statment. "The road may not reopen until after the shutdown."

National parks remain open during the government shutdown, but employees have been sent home—and aren't performing tasks like maintaining public restrooms. That's led to what might be described as a shit show.

"At the Point Reyes National Seashore in California, the buildup of human waste was so bad that the park had to be closed for health hazards," the Daily Beast reported today. Visitors to Yosemite National Park are reportedly relieving themselves by the roadsides. Pit toilets are overflowing at Rocky Mountain National Park in Colorado.

At least three people have died in national parks during the shutdown, although it remains difficult to directly link those deaths to staffing shortages.

Conservationists warn that overflowing human feces isn't merely disgusting—it endangers the parks' ecosystems.

"It is a ticking time bomb before something truly tragic happens," Nick Jones of the Sierra Club told The Daily Beast. "Our waste is potentially toxic to a lot of the species living in these places. Our waste carries different problems than that of the species living there."

Now Crater Lake National Park staff is circumventing that danger in Oregon by closing the road.

When the shutdown began, National Park Service staff explained that Crater Lake's government facilities would be closed—including the restrooms. But parks staff said restrooms run by a private contractor would remain open.

"The Rim Village Cafe & Gifts, which is run by a private company, will be open from 10:00 AM – 4:00 PM as long as the road to Rim Village remains open," the park website staff said. "There are restrooms inside the gift shop."

These have apparently proven insufficient.