As a single figure, the estimated $11.9 billion backlog of maintenance projects across the National Park System is staggering enough, but it grows in significance when you start to break it down by park: $631.6 million at Yellowstone, $840.3 million at the National Mall, $730.7 million at Gateway National Recreation Area, for example.

Equally staggering is the fact that from Fiscal Year 2006 through Fiscal Year 2015, the National Park Service spent roughly $10.5 billion on maintenance projects, and yet the overall price tag for the backlog continued to creep ever higher. While road maintenance needs claimed $6 billion of the outstanding $11.9 billion maintenance backlog, the rest is associated with water systems, buildings, campgrounds, trails, housing, waste water systems, dams, and utility systems.

In reviewing these needs, staff at the Government Accountability Office wondered whether the Park Service was tackling the backlog in the most efficient manner. To that point, it raised the question of whether the agency was taking a shrewd approach by placing a priority on projects deemed critical "to the operations and mission of a park unit or as having high visitor use."

"... several of the regional and park unit officials we interviewed said that the focus on high-priority assets may result in continued deterioration of less-critical assets, thereby increasing deferred maintenance," said the GAO report released this past Thursday.

The report was praised by U.S. Sens. Michael Enzi, R-Wyoming, and Lisa Murkowski, R-Alaska, who requested it.

"I appreciate GAO’s efforts to identify weaknesses and make recommendations that can improve how the Park Service manages its deferred maintenance backlog,” Sen. Murkowski said. “The longer our parks go without the attention they need, the more costly it will become for taxpayers to properly steward and restore these historical and cultural gems."

Added Sen. Enzi, "This report from the Government Accountability Office shines a revealing light on the billions of dollars in deferred maintenance on the park’s main infrastructure. It is vital that the National Park Service takes this issue seriously by improving efficiency and better prioritizing maintenance in order to ensure our parks are up to snuff.”

What the report failed to do, though, was stress Congress's responsibility to maintain the National Park System. While the GAO's mission is to "support the Congress in meeting its Constitutional responsibilities and to help improve the performance and ensure the accountability of the federal government for the benefit of the American people," its 54-page report stopped short of concluding that the Park Service is hamstrung by inadequate Congressional appropriations.

While the report did note that inflation has whittled away the value of the Park Service's annual appropriations, and that the number of park units is increasing without a proportionate increase in funding, it did not call on Congress to respond to those problems. Instead, its authors cited a variety of outside approaches, such as philanthropy, leasing, and volunteerism, that the Park Service is pursuing to make ends meet.

Indeed, where outside groups were once viewed as providing a "margin of excellence" atop the National Park System, more and more they're being expected to pay for infrastructure needs.

As a whole, the report paints the Park Service as an agency seemingly walking in place in trying to make significant inroads into the backlog, in large part because of funding issues.

Total funding for the Park Service increased about $0.6 billion, or 22 percent, from $2.65 billion in fiscal year 2006 to nearly $3.25 billion in fiscal year 2015. However, when adjusted for inflation, total funding for the Park Service increased by only $160 million in fiscal year 2015 dollars, or 5 percent, during this 10-year period. During this time, the number of park units in the system has grown from 390 in 2006 to 413 as of October 2016. Some Park Service officials said that this increase in park units meant that the agency’s appropriations had to be divided among an increasing number of units.

The report outlines just how daunting maintaining the National Park System and its more than 75,000 assets can be. In 1998, the last time the GAO examined the Park Service's maintenance backlog, the dollar total was estimated at $6.1 billion, of which some $5.6 billion was tied to construction projects. While President George W. Bush promised to wipe out the backlog, then pegged at $4.9 billion, when he took office, he never came close in five years.

When you appreciate the geologically active and storm-exposed landscape that the National Park System is draped over, you begin to realize the Sisyphean task the Park Service faces in maintaining the system when, at a moment's notice, disaster can strike. For example:

• Flooding in 2006 wiped out roads in both Mount Rainier and Glacier national parks
• Scotty's Castle and its access road at Death Valley National Park sustained an estimated $26 million in damage by October 2015 floods
• Road cracking and slippages frequently occur along the Blue Ridge Parkway and at Great Smoky Mountains National Park
• National seashores and other coastal park units almost annually suffer infrastructure damage from hurricanes
• Rockfalls lead to costly damage at parks such as Yosemite and Zion
• Maintaining high-elevation roads such as the Going-to-the-Sun Road in Glacier and Trail Ridge Road at Rocky Mountain National Park is costly.

Flooding wiped out sections of roads, and even campgrounds, in Mount Rainier National Park in 2006/NPS

At Yellowstone, where the movement of thermal "hot spots" can melt road surfaces and snowloads and below-zero temperatures bring their own pressures to bear on infrastructure, Superintendent Dan Wenk said the challenging environment has led the park to rely not only on federal appropriations but also concessionaires and philanthropic efforts to try to keep up with the maintenance needs.

"Yellowstone maintains over 1,500 buildings and 365 miles of primary roads. The park has a very short construction season and high costs due its remote nature," he said Friday. "Yellowstone successfully competes for funds. In addition, significant progress has been made to make improvements to NPS assets and through concession contracts to improve and maintain concessions facilities in order to enhance the visitor experience in the park."

All these unexpected incidents, unless responded to by Congress with a supplemental appropriation, which rarely happens, can, and often do, bleed the Park Service's financial resources. When an earthquake damaged the Washington Monument, and when its elevator was knocked out by mechanical troubles, it wasn't Congress but philanthropist David M. Rubenstein who paid for the repairs.

And when Scotty's Castle was damaged by the October 2016 floods, the Park Service looked to higher user fees, highway funds, and dollars from elsewhere within the National Park Service to pay for the repairs.

"In FY15, the National Park Service needed $820 million just to keep the backlog from growing," said John Garder, director of budget and appropriations for the National Parks Conservation Association. "But what they received is $473 million. Which means that they’re receiving 58 cents out of every dollar just to try to keep the backlog steady.”

Then, too, there's the sheer age of many of the assets. The GAO researchers determined that more than $3.8 billion of the backlog was tied to park units that were more than 100 years old. Parks established within the past four decades had a backlog of about $1 billion, they noted. And if you look closely at the GAO's charts, you'll notice that while paved roads claimed 50 percent of the backlog, they represent less than 16 percent of the park system's assets.

"The numbers show that (the Park Service) clearly needs a more dependable funding source" for roads and bridges, said Mr. Garder. "The (District of Columbia's) Memorial Bridge (repair project) alone is $250 million. That’s roughly the size of the annual funding for park infrastructure from the Highway Trust Fund. The entire amount, annually. That is what’s called a mega project. The (GAO) study doesn’t address these mega projects at all."

On Friday this rockfall came down on Zion National Park's scenic drive/NPS

And there is the tricky landscape to negotiate with infrastructure, as evidenced at Grand Canyon National Park and its ongoing woes with the Transcanyon Pipeline, which has drawn an estimated $100 million price tag for replacement.

Also to be considered are the growing crowds visiting the parks, which are scrambling to find solutions for how to cope with the increase or expanding the infrastructure footprint to deal with them, such as at Arches National Park in Utah where a larger parking area was installed for Delicate Arch. 

In trying to cope with these issues in times of waning federal appropriations, the Park Service has developed a variety of approaches to deal with maintenance needs.

• Park advocates are being relied on to raise more philanthropic dollars. The Grand Teton National Park Foundation played a key role in raising more than $17 million to repair the heavily used trail system at Jenny Lake, the Blue Ridge Parkway Foundation is working on a multi-phase campaign to repair the Moses H. Cone Memorial Park, both Friends of Acadia and Friends of the Smokies run successful trail maintenance programs in their respective parks, and the National Park Foundation expects to reach a $350 million goal it set for its Centennial Campaign for the National Park Service.
• Volunteers more and more are being counted on to perform work in the parks, from trail work to campground maintenance.
• Leasing aged facilities to organizations that are then required to rehabilitate and/or maintain them. Leasing operations at Golden Gate National Recreation Area and Hot Springs National Park bring in revenues for historic preservation and infrastructure maintenance.
• Outside organizations are brought in to run park operations, such as visitor centers and bookstores. "For example, the Park Service entered into a partnership with a nonprofit organization to operate and maintain the visitor center associated with Independence National Historical Park in Philadelphia. In this case, the Park Service owns the visitor center and contributes funds — about $800,000 annually — to cover some of its basic operating costs, but the nonprofit organization covers the majority of the facility’s operating and maintenance costs," the GAO report noted.
• Concessionaires are being engaged to run, and maintain, campgrounds in some parks.
• The Park Service is working with states to apply for transportation grants to address maintenance needs. "... the Tennessee Department of Transportation received a $10 million Department of Transportation grant — Transportation Investment Generating Economic Recovery (or TIGER) grant — to complete a section of the Foothills Parkway that runs through Great Smoky Mountains National Park, in North Carolina and Tennessee. The Park Service contributed an additional $10 million and the state contributed an additional $15 million in funds toward the $35 million project," reported the GAO.

Friends of Acadia helped the National Park Service build trails at Acadia National Park, such as the Quarry Trail/Friends of Acadia

While it's commendable that so many organizations rise to the occasion to help the parks, Congress needs to be held accountable for the plight of the Park Service, said Mr. Garder.

“As a homeowner, you can carefully prioritize your leaking roof and later demonstrate that to be a wise move for protecting your investment," he said. "But no amount of meticulous accounting, which is what they’re doing, is going to repair the leaking pipes in your basement without more money.”

How successful this multi-pronged approach the Park Service is pursuing to dealing with the maintenance backlog is unknown at this point, the GAO report said. The Park Service has developed a Capital Investment Strategy to rate maintenance projects, taking into consideration "financial sustainability, resource protection, visitor use, and health and safety."

For all fund sources except for line item construction, Park Service regional officials determine which maintenance projects are to receive funding by convening expert panels, which review the scored projects provided by the park units in their regions. For maintenance projects associated with the repair and rehabilitation fund source that are estimated to cost less than $1 million, the Park Service convenes a nationwide panel of experts to determine which will be funded. For line item construction projects estimated at more than $1 million, Park Service headquarters staff review and select which projects will receive funding. The Park Service identifies the line item construction projects the agency wants to fund by name, description, estimated cost, and project score in its annual budget justification submission to Congress.

However, this rating system has only just gotten under way, being used for the first time during Fiscal 2015. While some Park Service officials told the GAO that the Capital Investment Strategy has helped them prioritize maintenance needs in their parks, others worried that the ratings "could result in continued deterioration" of lesser-ranked projects and so lead to increased deferred maintenance.

"By evaluating the Capital Investment Strategy and its results after it has been in place for a few years, the Park Service may be able to determine if the strategy is achieving its intended outcomes or if changes need to be made," the GAO concluded.

While NPCA's Mr. Garder didn't quibble with that recommendation, he thought it fell short.

“This is a helpful recommendation to the Park Servide to track their complex accounting system, and we embrace that," he said. "But there is a very important missing piece here. A conclusion that we draw is that incoming Interior Secretary (Ryan) Zinke (if his nomination is approved) should work within the administration and the Congress to pursue a more robust approach to the backlog. That should be done by increasing current funding sources ... as well as legislation that dedicates funding to the backlog.”

Lobbying for increases in funding for the Park Service are NPCA, the Pew Charitable Trusts, and other national, state, and local organizations.

At Pew, officials have an ongoing campaign to encourage Congress to better fund the Park Service. Launched last year, the campaign seeks a dedicated funding stream for national park repairs, policy reforms to prevent the maintenance price tag from growing, more funding to repair roads and bridges in the park system, and more "opportunities for public-private collaboration and donations to address park maintenance."