(RNS) A national alliance of public employees is accusing the National Park Service of “leadership paralysis” for not addressing questions about religious displays at federal parks.

The group Public Employees for Environmental Responsibility had asked the Park Service last September about plaques containing biblical psalms at Grand Canyon National Park in Arizona and a stupa (a Buddhist religious monument) at Petroglyph National Monument in New Mexico.

The organization questions whether the displays are constitutional.

“When it comes to religious displays, Park Service leadership reacts like a deer in the headlights — afraid to move but frozen in an indefensible position,” said Jeff Ruch, executive director of the alliance in a Thursday (March 31) statement.

An official of the National Park Service’s Intermountain Region had responded on March 3, saying the Park Service is consulting with lawyers at the Department of Interior and “intends to review these religious expressions in these two parks.”

James Doyle, spokesman for the Park Service’s Intermountain Region, told The Denver Post that officials are addressing the issue.

“We are dealing with this,” he said, “but dealing with religious displays is not easy. We want to be respectful of the separation of church and state, but it’s sometimes difficult to tell the history of the U.S. without preserving the role religion has played.”