“How we treat our land, how we build upon it, how we act toward our air and water, will in the long run tell what kind of people we really are.” These words, spoken by philanthropist Laurance S. Rockefeller, reflect the passion that philanthropists large and small exhibit when they invest in the National Park System. Whether the Congress as a whole embraces that passion remains to be seen.

As Congress works in the coming months to reach accord on legislation that would provide billions of dollars to address the National Park System's nearly $12 billion in maintenance work that's been put off for a year or longer, the backlog continues to inch higher and higher. If a funding mechanism is passed, then the National Park Service will have to craft a national priority list of projects that need to be tackled. While that list doesn't exist yet, here's a look at some possible top priorities.

Across the National Park System, maintenance needs are creating safety issues for park visitors. Whether it's the leaking Trans-Canyon Pipeline at Grand Canyon National Park, eroding walls at San Francisco Maritime National Historical Park, or cracks in the Blue Ridge Parkway, tens of millions of dollars in deferred maintenance are dangerous for visitors.