LAS VEGAS (AP) — A massive wildlife refuge north of Las Vegas established to protect desert bighorn sheep is severely understaffed.

 Amy Sprunger, manager of the Desert National Wildlife Refuge, is set to become the only employee at the 2,500-square-mile (6,475-square-kilometer) refuge in January.

Sprunger told the Las Vegas Sun that the refuge, the largest in the Lower 48 states, is supposed to have three full-time employees, but that’s “barely enough to scratch the surface.”

Nevada’s other national wildlife refuges have similar staffing challenges.

Ash Meadows in the Amargosa Valley has three full-time employees. Pahranagat in Lincoln County has two, and Moapa Valley near Valley of Fire State Park shares an employee with Pahranagat.

Caroline Brouwer, vice president of government affairs at the nonprofit National Wildlife Refuge Association, said funding for the National Wildlife Refuge System has decreased or failed to keep up with inflation and costs of living over the past decade, leading to staff shortages.

Brouwer said half of all 562 refuges now have no full-time staffers.

Marge Kolar, who oversaw all refuges in Nevada and California from 1994 to 2013, said the trend predates President Donald Trump’s administration.

The Trump administration has proposed funding the refuge system with $509.5 million for fiscal year 2020, the highest amount ever requested, but Brouwer estimates that figure still hasn’t kept up with inflation.

“If funding had stayed level and kept pace with those inflationary costs in 2010, the refuge system would be funded at about $575 million right now,” Brouwer said.

The tight budget at Desert National Wildlife Refuge means Sprunger and any other employees have to perform a mix of managerial and administrative jobs, while about 20 regular volunteers pick up the slack.

“We wouldn’t be able to open our front doors without the volunteers, that’s for sure,” Sprunger said.

She hopes to hire a biologist soon, after more than a year without one. The only other employee, a maintenance worker, is retiring at the end of 2019.

Kevin DesRoberts, a project leader for the four southern Nevada refuges, said paid employees are overworked and that volunteers do work equal to that of about eight full-time staffers.

He said the lack of staff particularly affects the ability to control and treat invasive plants.

Brouwer said refuges are not as well known as national parks and conservation areas and that could be why they get less funding and attention.

“People talk about parks all the time, and the parks are decently well funded,” she said. “The refuge system doesn’t have the visitors that the parks do, and I think that contributes to this.”

Desert National, Pahranagat and Ash Meadows all saw between about 42,000 and 56,000 visitors in the 2018 budget year, while Moapa Valley got about 900 visitors.

Red Rock Canyon National Conservation Area near Las Vegas, by comparison, had about 3 million visitors, and Death Valley National Park, about a two-hour drive from Las Vegas, had 1.6 million.