Washington's partial shutdown, which has cut off some government services, entered its 12th day on Wednesday with no end in sight.

It stems from an impasse between congressional Democrats, who control the House of Representatives as of Thursday, and President Donald Trump, who is demanding $5.6 billion in funding for a border wall.

The impact is being felt from national parks to immigration courts, while prospects for an imminent end to the showdown remained unclear.

WASHINGTON/JOSHUA TREE NATIONAL PARK, Calif. (Reuters) - As Ralph Snake walked across Washington’s National Mall on Wednesday, he stopped every few feet to pick up some of the litter that has accumulated in the once-tidy expanse of grass since a budget showdown partially closed the federal government nearly two weeks ago.

“I decided 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.

Snake came to the U.S. capital to witness Sharice Davids get sworn in as one of the first two women of native American descent to become members of Congress. “Just because this thing is shut down, our hearts aren’t shut down,” he added.

The partial shutdown, which has cut off many government services, entered its 12th day on Wednesday with no end in sight. It stems from an impasse between congressional Democrats, who control the House of Representatives as of Thursday, and President Donald Trump, who is demanding $5.6 billion in funding for a border wall.

National parks have closed campgrounds out of fear that toilets will overflow with human waste. Hundreds of thousands of federal employees are working without pay. The immigration court system, already suffocating under a massive backlog, is largely shuttered.

The prospects for an end to the showdown remained unclear, even as congressional leaders visited the White House on Wednesday.

In Washington, the 17 museums run by the Smithsonian as well as the National Zoo closed their doors on Wednesday after running out of emergency funding, leaving tourists frustrated with politicians of all stripes.

“It’s stupid,” said Laura Vanbragt, a 20-year-old student from Grand Rapids, Michigan. “There should just be more communication between the two, more give on both sides.”

Outside the Bureau of Engraving and Printing, Clint Woods and his family stood in line waiting for a guided tour with other visitors who were locked out of more popular venues.

“It’s like two squabbling children,” Woods, 43, said of Trump and Democratic leaders in Congress. “They both think they’re right, and they’re dug in.”

California’s Joshua Tree National Park, about 130 miles (209 km) east of Los Angeles, is among many national parks across the country that have curtailed operations. It closed some campgrounds on Wednesday because outdoor toilets, which cannot be emptied due to a lack of staffing, have reached capacity, creating a potential health hazard.

Read more: Trump and Democrats dig in their heels as the partial government shutdown extends into the new year with no end in sight

Victor Jerez, 53, spent the day hiking in Joshua Tree with his brother, his sister and their families, though they were disappointed to find the visitor center shut down.

“It would have been nice to have some trail maps and to get some recommendations from the staff,” said Jerez, who was visiting from Europe, where he splits his time between Barcelona and London.

Prickly pear Opuntia basilaris in bloom in spring in the desert in Joshua Tree National Park California. Education Images/UIG via Getty Images

Working without pay

Unlike in some previous government shutdowns, many national parks have remained open, though without staff to collect trash and service restrooms. Advocates have voiced alarm that an extended shutdown could cause environmental damage.

“We’re very concerned about the reports we’re seeing of human waste in inappropriate places,” said John Garder, senior director of budget and appropriations for the National Parks Conservation Association. “Trash is a serious concern for wildlife.”

The impact of the shutdown has reached the nation’s 62 immigration courts as well. Hundreds of judges are on furlough, and only cases of immigrants in detention are being heard.

The Trump administration has expanded the system, which is run by the U.S. Department of Justice, aiming to cut down on the backlog of more than 800,000 cases, but the shutdown will complicate that effort, said Ashley Tabaddor, the president of the national immigration judges’ union.

“To reschedule these cases can take several years because the judges are all booked,” she said.

A Justice Department spokesman said he could not respond to a request for comment because of the shutdown.

Meanwhile, some 800,000 government workers are either furloughed or working without pay until the shutdown ends.

Shekina Givens, a 32-year-old Transportation Security Administration officer in Atlanta and president of the local chapter of a union that represents government employees, said she is avoiding using her credit cards and putting off some expenses.

“I’m the only person that’s working in my household and paying all the bills,” she said.