We preservationists see the world differently. Sometimes we see buildings through rose-colored glasses, but more often than not, our eyes are immediately drawn to rotting sills; mold; and—horror of horrors—missing gutters, siding, windows, and roofs. While these can be minor problems when taken individually, the challenge we routinely face is a slew of major repairs that have been postponed—whether in our historic house museums, Main Streets, school systems, or national parks.

The national park system consists of 413 areas that tell the story of remarkable people and events in our nation’s rich history through sites as diverse as Vicksburg National Military Park, Independence Hall, the Statue of Liberty, the Martin Luther King Jr. National Historic Site, and Native American cultural sites like Mesa Verde National Park. So it’s no wonder that our national parks, and the historic and cultural sites they protect, are also some of our nation’s most significant attractions. In 2015 alone they generated more than 307 million visits, with visitors spending an estimated $16.9 billion in nearby communities—which supported 295,300 jobs and provided a $32 billion boost to the national economy.

Unfortunately, inconsistent public funding has resulted in a deferred maintenance backlog in our national park system estimated to be about $12 billion dollars (for financial year 2015), of which more than $3 billion is attributed to historic, non-transportation-related structures and sites. As a result, some of our most significant historic sites are at risk of falling into disrepair. For example, the Statue of Liberty National Monument in New York Harbor, which includes Ellis Island—an iconic symbol of American freedom and immigration—has repair needs of more than $160 million.

This is why the National Trust has joined with the Pew Charitable Trusts and the National Park Conservation Association in a national campaign that seeks to address the deferred maintenance backlog with a reliable, dedicated federal funding source from Congress. To kick off this campaign, the National Trust launched a new webpage that will be routinely updated with new tools, research, and news. A recent webinar featured Yaron Miller with the Pew Charitable Trusts and Pam Bowman, director of public lands at the National Trust, describing ways to get involved in the campaign.

During the discussion, Bowman cited a 2016 Pew Charitable Trust survey in which 44 percent of respondents ranked the preservation of historic and cultural sites and monuments as their top priority for repair in the national parks—higher than any other category of infrastructure repair need. They clearly recognized that deferred maintenance puts historic and cultural sites at risk of permanent damage or loss.

The joint campaign is the latest effort by the National Trust to help the National Park Service address the repair backlog. Three years ago the National Trust, along with The Corps Network, launched HOPE Crew—an initiative to train more young, diverse people in preservation while protecting historic cultural sites on public lands. The program is now in its third year, and HOPE Crews recently successfully finished their 80th rehabilitation project. These large-scale projects make a huge difference. This year project director Monica Rhodes collaborated with the National Center for Preservation Technology and Training, local masons in New Orleans, and 800 volunteers to clean and realign more than 8,000 veteran headstones in Chalmette National Park.

Three years ago the National Trust also released a report describing the legal authority of the National Park Service to enter into historic leases and cooperative partnerships with non-federal partners and detailing some of the barriers such agreements face. Leasing historic buildings provides opportunities for the National Park Service to leverage private financial sources to maintain historic resources for future generations.

Historic and cultural sites in the national park system are living testaments to our valor, hardships, victories, and American traditions. We have a responsibility to ensure that our parks are maintained and preserved for future generations. Join our campaign by urging Congress to address the deferred maintenance backlog in our nation’s parks so that the public can continue to learn from and enjoy the stories that tell our nation’s history.

Renee Kuhlman is the director of policy outreach at the National Trust for Historic Preservation.