YELLOWSTONE NATIONAL PARK, WYO. โ€” Attendees at an outdoor concert held near Yellowstone National Park last week as part of the National Park Service’s Centennial Celebration were told to expect traffic jams, parking hassles and long lines for admission.

While the Aug. 25 event brought less congestion than anticipated, that same advisory could also apply to many summer days in Yellowstone itself.

The celebration held in Gardiner, Mont. near the iconic Roosevelt Arch at the park’s north entrance drew an estimated 6,000 people who listened to speeches from Interior Secretary Sally Jewell and actor Bill Pullman, as well as musical performances by Emmylou Harris and John Prine.

The event was one of dozens held this year throughout national parks across the country. Park Service officials are hoping the agency’s Centennial celebrations will attract younger, more diverse visitors, even while the most popular sites endure seasonal waves of tourists that tax infrastructure and threaten fragile natural resources.

Park managers in Yellowstone and elsewhere face a range of daunting challenges, including a warming climate, growing crowds and tight budgets.

“We need to be supported by all Americans,” Park Service Director Jonathan Jarvis said at a press conference before Thursday’s concert. The agencies core supporters are “not reflective of the diversity of our nation, which is increasingly urban, diverse and tech-connected,” he said.

Jarvis said the Park Service is “chronically underfunded,” and should be funded through an endowment, rather than relying on Congressional budget appropriations that are tangled in politics and plagued by uncertainty.

The agency has 22,000 employees and an annual budget of $3.4 billion, but has failed to keep pace with a growing backlog of deferred maintenance now totaling $11.9 billion, including more than $630 million of repairs and other work in Yellowstone.

The Park Service has faced criticism for a growing reliance on funds from corporate donors and nonprofit “friends of the parks” groups to help address budget shortfalls.

Yellowstone Superintendent Dan Wenk defended the fundraising efforts, saying the nonprofit Yellowstone Park Foundation had raised more than $100 million over two decades for key projects and initiatives.

Parks retain a majority of entry fees for local use, and Yellowstone last year hiked its entrance fee by $5 to $30. That move helped raise millions in extra revenue, as the park saw 2015 attendance jump by 17 percent to a record 4.1 million visitors, bringing snarled traffic and parking nightmares to busy spots for much of the summer.

Better planning for this year โ€” along with increased staffing at entry gates and installing more restroom sites โ€” has eased congestions issues, Wenk said.

Josie Hedderman, an event planner from Cody, Wyoming, near Yellowstone’s east entrance, said she usually avoids the park during the busiest summer weeks, but found herself marveling at how the 2.2 million acre (8,900 square km) preserve was “bursting at the seams” in July. “I was astounded at how crowded it was,” she said.

Hedderman said she was “thrilled” by the Centennial celebration, and was impressed with how smoothly things ran. But solving Yellowstone’s larger congestion issues “will be a huge problem, because it’s becoming less enjoyable for people who visit,” she said.

Wenk said fixing congestion woes is”not a process that can be done easily or quickly.”

Hedderman said it was important to preserve Yellowstone and similar places.

“Society in general seems out of touch with wild places and wild things,” she said, “and Yellowstone is one of the last places people can see anything like this.”

Contact Ruffin Prevost at 307-213-9818 or [email protected].

Ruffin Prevost is founding editor of Yellowstone Gate, an independent, online news service about Yellowstone and Grand Teton parks and their gateway communities. He lives in Cody, Wyo., where he also works...