With three years to go until the National Park Service celebrates its centennial, a bipartisan coalition of U.S senators and representatives is asking Pres. Obama to work with them on developing and executing a “bipartisan, dynamic, and effective initiative to commemorate the national park centennial and prepare our national parks for their second century of service to the American people.”

The letter, signed by more than 200 members of Congress, is just the latest attempt to get the Congress and the White House united in an effort to burnish the National Park Service and the National Park System in advance of the centennial celebration that arrives in August 2016.

When he first came into office, President George W. Bush carried a promise to wipe out the Park Service's outstanding maintenance backlog of roughly $5 billion before he left office. That goal was never achieved, and the maintenance backlog has more than doubled.

Also during his term in office President Bush supported the so-called Centennial Challenge to match federal dollars with privately donated dollars to benefit the Park Service. That effort got relatively little support from Congress during his two terms, and never caught fire under President Barack Obama.

In their letter to the president, the politicians wrote that “the national park centennial provides an opportunity to reinvigorate the national parks for their second century of service. We look forward to working with you and your staff to build on momentum from the 100th anniversary of the National Parks System (sic) to find a sustainable path forward for our national parks.”

Among those signing the letter were U.S. Sens. Mark Udall, D-Colorado, and Rob Portman, R-Ohio, who sit on the Senate National Parks Subcommittee, and U.S. Reps. Dave Reichert, R-Washington, and Ron Kind, D-Wisconsin.

Applauding the letter to the president was the National Parks Conservation Association.

“As this letter demonstrates, national parks are unifiers, regardless of politics or place,” said Craig, senior vice president of government affairs for the association. “They are red, white and blue, not red, purple or blue. With support on both ends of Pennsylvania Avenue, now is the time for the White House and Congress to act together and provide for the future of our national parks, for our children and grandchildren.”

Also hopeful that the letter would spur action was Bess Averett, executive director of Friends of Vicksburg National Military Park in Mississippi. “We hope the president will hear Congress’s call and work with both parties to ensure a meaningful centennial initiative that can provide the national parks with real support,” she said. “In Mississippi, we are well aware of the importance of preserving the national Park system for future generations.”

Interestingly, the letter comes less than a week after the Senate Energy and Natural Resources Committee held a hearing into whether partnerships with private businesses and organizations could help the Park Service overcome its massive maintenance backlog.

"We ought to be looking at fresh ideas, creative new ideas that bring in the private sector, look to public-private partnerships to do a responsible job of the needs of our parks in a fiscally challenging environment,” said Sen. Ron Wyden, a Democrat from Oregon.

At that hearing, however, Interior Secretary Sally Jewell cautioned the senators not to turn their backs on the federal government’s responsibility for the national parks.

“Private philanthropy should be the margin of excellence for the parks, not the margin for survival,” the Interior secretary said. “It’s critically important that we step up as a federal government to support these assets that are so important.”