Alternative B is the only alternative that designates the Clarks Fork Basin/Polecat Bench West Paleontological area as an ACEC, and would be the most effective for protecting the paleontological values of concern. Alternative B also would be the most restrictive to surface-disturbing activities, mineral development, ROWs, and motorized travel. Alternative B includes specific requirements related to paleontological sensitivity surveys and monitoring that would benefit the protection of the values of concern and would not exist under the other alternatives. The management of mineral development would be similar under alternatives A and C, but ROW and motorized travel management under Alternative C would be more restrictive than under Alternative A. A portion of the Clarks Fork Basin/Polecat Bench West Paleontological area is included in the PETM ACEC under Alternative D; the Paleocene-Eocene Thermal Maximum section describes management of and impacts to this area under Alternative D.