From Independence Hall in Philadelphia to the redwood forest in California's Sequoia National Park, the country's national parks today are celebrating the 100th anniversary of President Woodrow Wilson's signing of the National Park Service Act, which established the agency that protects our natural and historical riches.

It's hard to be too festive though when the more than 400 parks, monuments, museums and reserves in this country are struggling. Budget cuts, climate change, and a new view of how to best protect the delicate ecosystems where yellow-legged frogs, bighorn sheep, and buffalo roam are straining the sites, which annually are visited by about 275 million people.

The service's $3 billion budget, which comes from visitor fees and federal taxes, hardly covers the agency's operating costs let alone pay for needed expansion and maintenance. The budget is also 15 percent less than it was just 15 years ago, despite the parks' enormous popularity.

A recent joint study by Harvard and Colorado State Universities found that "95 percent of the American public said that protecting national parks for future generations was important, and 80 percent would pay higher federal taxes to ensure the protection and preservation of the National Park System."

The Park Service estimates it would cost $12 billion to merely keep up with maintenance on its 18,000 miles of trails, plus roads, bridges, campgrounds, and other facilities. Parks advocates want an endowment to give the service a more stable source of funding to plan projects and expand services. But bills to create the endowment, expand the parks' number of volunteers, or provide other forms of aid, have languished in Congress.

Just like with the rest of the nation, extremely sensitive natural areas in the park system have suffered through climate change, which has produced wildfires, floods, melting glaciers, and rising sea levels.

Recent wildfires threatened Yellowstone National Park in Wyoming while summer floods at Zion National Park in Utah caused officials to limit access to popular hiking trails. Also threatened by rising sea levels is Assateague Island, located off Maryland's eastern shore, which is considered the most vulnerable national seashore in the park system.

With so few natural expanses unmarked by housing developments and strip malls, it is vital to this nation's interests to properly maintain its 84 million acres of parks, refuges, and battlefields.

In doing that it is important to heed the warning of environmental scientists that protecting areas beyond a park's boundaries is necessary to protect the 247 threatened or endangered species of plants and animals that live within them. That means giving the parks reasonably large buffer zones to keep ecosystems intact.

Congress needs to make the preservation of our national parks a higher priority. That includes giving the Park Service the ability to expand programs that teach children how they can become stewards of our national treasures.