DENVER – From the Grand Canyon to Old Faithful to the Great Smoky Mountains, millions of tourists flocking to national parks this summer will find bears, bison and other wildlife in abundance. They'll wade in crystal clear streams, stare up at towering redwoods and marvel at the Milky Way dusting the dark night sky.

There's one thing they're sure to see less of: National Park Service law enforcement rangers, whose numbers have declined for decades despite huge increases in park visitation, according to an exclusive analysis conducted by the USA TODAY Network using data obtained via the federal Freedom of Information Act. Former park managers and longtime park advocates said the shrinking staff means the broad-hatted rangers spend less time patrolling backcountry areas to keep animals and people safe.

“It’s a tough time," said Phil Francis, a former park service superintendent who retired in 2013 after a 41-year career that began as a law enforcement ranger. Francis is chairman of the nonprofit Coalition to Protect America's National Parks. "The superintendents are having to make tough decisions about what jobs to fill due to inadequate funding," he said. "Do you fill a maintenance job, or do you fill law enforcement or run visitor centers?”

The number of law enforcement rangers has declined by more than 20% since 2005, dropping to 1,766 full-time and seasonal rangers in June, according to park service data.

National parks are seeing historically high visitation numbers: 318.2 million recreation visits last year and nearly 331 million each in 2017 and 2016, during the Park Service's Centennial celebration. In contrast, the nation's parks saw 273.4 million visitors in 2005, when there were 1,922 full-time and seasonal law enforcement rangers.

There's been an overall decline in park service staffing, which has dropped 20% over the past decade. The number of “full-time equivalent” National Park Service employees, which includes permanent, temporary and seasonal workers of all kinds, from interpretive specialists to maintenance workers, is 22,076, down from 27,484 in June 2010, according to park service data.

Budget cuts, as well as a long-standing battle within park service leadership over the appropriate role of armed police within America's national parks, have fueled the staff reductions.

It adds up to much fewer rangers and many more visitors. Critics said the problems are going to get worse as the Trump administration works to shrink the size of federal government, which includes trimming the National Parks Service operating budget.

“The thin green line patrolling our national parks is in danger of snapping," said Jeff Ruch, executive director of the Washington-based Public Employees for Environmental Responsibility, a nonprofit group that advocates for public transparency and provides whistleblower services for current or former government employees.

Death on the trail

Former rangers said the diminishing number of law enforcement officers means visitors may have to wait longer for help, increasing safety risks in remote areas that were already hard to effectively patrol.

Hiker and military veteran Ronald Sanchez Jr., 43, of Oklahoma City, was killed May 11 on the Appalachian Trail, a winding 2,200-mile-long footpath from Georgia to Maine overseen by the park service.

Under normal circumstances, the Appalachian Trail has two full-time rangers assigned to manage and monitor hikers, and to coordinate communication with the sheriffs and police departments along its route. Because of reassignments, it's overseen today only by a head ranger on loan from another park who is assisted by other rangers working part-time patrols while maintaining their own positions elsewhere.

On the night of May 11, Sanchez, an Army veteran who served three tours in Iraq, and three others were camped in a remote area of the trail in Smyth County, Virginia, when they were approached by a man who allegedly threatened to pour gas on their tents and burn them to death. Investigators said two of the hikers ran away and called 911. The man then fatally stabbed Sanchez and wounded his hiking partner, who hiked 6 miles while bleeding to get help, law enforcement officials said.

It took sheriff's deputies nearly four hours to reach the campsite where Sanchez died. Investigators said the two hikers who initially fled identified the suspect, James Jordan, via a photo on their cellphone because they had been warned about him by other hikers farther down the trail.

Multiple Appalachian Trail hikers had flagged Jordan as a threat – he was even briefly jailed by a sheriff in Tennessee. Jordan faces charges of murder and assault with intent to murder. His case is on hold while authorities investigate whether he's mentally incompetent.

A park system the size of two Floridas

A big part of the park service's law enforcement challenge is the sheer size and diversity of its sites and facilities, from the historic lodges rimming the Grand Canyon in Arizona to the climbing camps of California's Yosemite National Park and the 444-mile-long Natchez Trace Parkway, a winding low-speed road through Mississippi, Alabama and Tennessee that traces historic trading and migration trails.

The National Park Service, which has a $3.2 billion budget, is responsible for more than 84 million acres of land, the equivalent of two Floridas, starting with the first national park, Yellowstone – spread across Wyoming, Montana and Idaho – which was initially patrolled by the U.S. Army because it was deemed so valuable.

The increase in visitation, up roughly 20% in the past decade, should have in theory resulted in increased law enforcement, in the same way that a growing city adds more police officers. That hasn't happened.

The service manages 417 park units, 23 national scenic and national historic trails and 60 wild and scenic rivers with fewer rangers than it did two decades ago.

“It’s a sad state of affairs," said Paul Stevens, who retired in 2015 from his post as chief ranger for North Carolina's Cape Hatteras National Seashore, which stretches 70 miles along the Outer Banks.

Stevens, 59, said he left his job in part because of budget cuts at the park, which reduced ranger staffing. "There’s definitely a negative aspect, without a doubt,” he said.

Trump administration shifts focus

Critics say parks have been underfunded for decades by Democratic and Republican presidents. The Trump administration exacerbated staffing shortages by shifting some rangers and National Park Police officers, who patrol the Statue of Liberty and the Washington Monument, into border areas such as Arizona's Organ Pipe Cactus National Monument, a common site for illegal crossings by drug traffickers. In the past two years, rangers have seized more than 600 pounds of marijuana and made multiple arrests.

Stevens said that even during the best of times when he had a large staff, it could take a ranger 30 minutes to respond to a call for help at Cape Hatteras, because there was rarely more than a handful of law enforcement rangers working at any one time. Cutting rangers invariably causes longer delays, he said, and forces parks to call on police departments for help during emergencies, such as car crashes or assaults.

"Who are the ones really protecting the resource? It’s not the people doing the bird surveys, it’s the law enforcement rangers," Stevens said. "When the bad things happen that people do, we're the first ones called."

National Park Service officials said they're trying to balance competing needs when funding is tight. The park service has never had a large law enforcement corps, in part because many park superintendents downplay the presence of armed officers to help visitors feel welcome.

"Generally, law enforcement program budgets are controlled at the local level, thus park superintendents, using a risk-based approach, ultimately decide which programs and/or positions are prioritized for funding and staffing," NPS spokeswoman Kathy Kupper said.

Taken at the individual park level, the overall decline in numbers doesn't seem significant. Rocky Mountain National Park, for instance, has 16 authorized ranger positions but only 14 full-time rangers on the job because two posts remain unfilled. However, the park is twice the size of Chicago, and last year, it saw a record 4.6 million visitors. In 2015, when the park had one additional ranger, visitation was 4.2 million.

In other words, the ranger-to-visitor ratio went from one ranger per 277,000 visitors in 2015 to one ranger per 328,000 visitors last year. And Rocky Mountain is the country's third-busiest park.

"It seems kind of weird that the employee count is decreasing," said Mira Rodriguez, 24, who was visiting Rocky Mountain National Park with her father, who shipped his Acura SUV over from Hawaii so they could visit a dozen national parks across the West. Rodriguez, a teacher in Las Vegas, said she hadn't felt the first five parks they visited were understaffed but knew visitation had been going up overall.

"As long as they have enough rangers to manage the traffic, I'm happy," said Ricardo Rodriguez, her father, as he proudly showed off his Hawaii license plate.

National parks relying on volunteers for law enforcement

At the Blue Ridge Parkway, there are only 30 rangers to patrol 83,000 acres of land, 1,110 boundary miles and 469 miles of the mountainous Depression-era road across the spine of the Blue Ridge Mountains from Shenandoah National Park in Virginia to Great Smoky Mountains National Park in North Carolina. The park has 34 ranger positions but, like many other national parks, hasn't been able to keep all those posts filled despite hosting 14.7 million visitors last year. That's a 12% drop in staffing from what's authorized.

Park officials are trying to hire more law enforcement rangers and use volunteers to patrol some areas.

“I think if you can ask any law enforcement agency out there, they’ll say they need more folks," said Neal Labrie, chief law enforcement ranger at the Blue Ridge Parkway.

Labrie's rangers respond to thousands of calls for service annually, from theft and speeding to rape and murder. In 2018, there were 20 fatalities in the park, most from motor vehicle accidents and suicides.

Other rangers said they do what they can with the resources they have. Some parks use more volunteers, while others, including Great Smoky Mountains National Park, which straddles the North Carolina-Tennesee border, use more surveillance cameras and train janitors to help with backcountry rescues. The park has 32 rangers working or undergoing the hiring process, down from 37 rangers 20 years ago.

"Times are lean. We recruit people who are very passionate," Great Smoky Superintendent Clayton Jordan said. "We recruit people who like to work hard. You would not come to the Smokies if you were looking for Sleepy Hollow.”