A group of former National Park Service chief historians and park superintendents are plaintiffs in a lawsuit filed Thursday to block expansion of the visitor center at the Little Bighorn Battlefield National Monument. At stake, they say, is the historic integrity of the monument.

The lawsuit was filed by Public Employees for Environmental Responsibility. The plaintiffs include two former chief historians of the National Park Service, three former superintendents of the Little Bighorn National Battlefield, the Custer Battlefield Historical & Museum Association, as well as Little Bighorn historians.

Although NPS Director Mary Bomar has agreed to give the project further consideration, the project has legal clearance to proceed absent a lawsuit.

The Park Service plans include erecting an enclosed theater seating 200 people at the base of Last Stand Hill, site of the climax of the 1876 battle in which General George Armstrong Custer and five companies of the 7th Cavalry were wiped out. The lawsuit claims the project would occupy the middle of the battlefield, blocking views of how the battle evolved as well as where it ended.

"The existing Visitor Center was built in an intrusive location in 1952 and is almost universally regarded as an adverse effect. Any expansion will worsen the adverse effects on the historical and cultural aspects of the Battlefield," stated former NPS Chief Historian Robert Utley, a plaintiff in the case who has authored two versions of the Battlefield's official historic handbook, a biography of General Custer, and several other books concerning the Sioux Indian wars.

"The proposed enlargement obviates a chance to do the right thing for the battlefield and its interpretation and continues a pattern that has been going on for nearly four decades," said Jerome A. Greene, another plaintiff who is a retired NPS research historian and author of Stricken Field: The Little Bighorn since 1876.

Mr. Greene noted that the 1986 General Management Plan for the park calls for a new visitor center out of the battle sightlines and near where the battle started rather than where the NPS now proposes. "This band-aid approach perpetuates an outmoded structure in the wrong place on the historic ground," he said.

On April 23, 2008, the NPS cleared the project for construction by finding that it would have "no significant impact". The PEER lawsuit argues that the agency's failure to adequately consider alternatives and impacts violates both the National Environmental Policy Act and the National Historic Preservation Act as well as the Park Service's own Management Policies.

As recently as last year, NPS conceded that the project would have an "adverse impact" on the Battlefield but reversed that finding without explanation, according to PEER.

"The law requires the Park Service to engage in a full and honest review of available options and potential effects but that full and honest review is missing on this project," commented PEER Senior Counsel Paula Dinerstein, who filed the complaint in U.S. District Court in Washington, D.C. "Unfortunately, the Park Service has decided to turn a deaf ear to the advice from its most distinguished officials and other experts who dedicated their careers to protecting our historical heritage."