WASHINGTON (AP) — A group of former national park superintendents is calling on the Trump administration to close the parks to visitors in case of a government shutdown.

Past shutdowns where parks remained open have resulted in vandalism of iconic symbols, destruction of wildlife habitats, and possible endangerment of visitors, as articulated by 40 former superintendents in a letter to Interior Secretary Doug Burgum.

The former officials stated that a shutdown now could be even more detrimental due to existing strains from a 24% reduction in staff and severe budget cuts. A secretarial order by Burgum that directed parks to remain open has already led to neglect in trash collection and other essential maintenance, the letter notes. The order suggests that the Park Service director should ensure all park units remain open and accessible during their designated hours.

“Leaving parks partially open during a shutdown with minimal staffing is reckless,” the former officials stated in their correspondence.

The letter was organized by the Coalition to Protect America’s National Parks and the Association of National Park Rangers. Despite requests, the Interior Department and National Park Service did not respond to queries for comment.

“National parks don’t run themselves. It is hardworking National Park Service employees that keep them safe, clean and accessible,” they added.

The former superintendents urged prioritization of conservation and visitor safety during potential shutdowns and highlighted that park staff manage everything from routine maintenance, educational programs to long-term projects that are crucial for parks’ ongoing operations.