The National Forest System: Cultural Resources at Risk was prepared by the National Trust for Historic Preservation and T. Destry Jarvis, former Senior Advisor to the Assistant Secretary of the Interior and currently President of Outdoor Recreation and Park Services, LLC. It urges the Forest Service to survey its assets.

"There are literally thousands of other sites spanning all 193 million acres of National Forest that have yet to be identified, let alone protected," National Trust President Richard Moe said in a statement today.

According to the report, 80 percent of Forest Service land—and almost 200,000 sites—have not been surveyed for cultural, archaeological and historic resources. The Forest Service owns 325,000 sites, and fewer than 2,000 appear on the National Register of Historic Places, according to the report.

The report makes 11 recommendations, including one to revise the 1976 National Forest Management Act to "explicitly recognize the agency's responsibility for historic and cultural resources." It also suggests the Forest Service restrict off-road vehicles by amending its Travel Management Rule.