______, within the Custer Gallatin, Helena or Lewis and Clark National Forest and land administered by the Lewistown Field Office of the Bureau of Land Management are designated as the Greater Glacier/Greater Yellowstone Corridor and shall be subject to the special corridor management requirements under section 203. (s) Mt. Leidy Highlands/Wind River Range Corridors Certain Federal land comprising approximately 69,000 acres, as generally depicted on the map entitled _____ and dated ______, within the Bridger-Teton or Shoshone National Forest and land administered by the Lewistown Field Office of the Bureau of Land Management are designated as the Mt. Leidy Highlands/Wind River Range Corridor and shall be subject to the special corridor management requirements under section 203. 203. Treatment of biological connecting corridors Those portions of the biological connecting corridors designated by section 202 are hereby designated as special corridor management areas and shall be managed according to the Multiple-Use Sustained-Yield Act of 1960 ( 16 U.S.C. 528 et seq.) and other applicable laws, and in the following manner: (1) The practice of even-aged silvicultural management and timber harvesting is prohibited within the special corridor management areas. (2) Subject to valid existing rights, mining, oil, and gas exploration and development and new road construction or reconstruction is prohibited within the special corridor management areas. (3) The Federal land management agency responsible for the administration of a special corridor management area or portion thereof shall take immediate steps to ensure that road densities within the biological connecting corridor approach, as nearly as possible, zero miles of road per square mile of land area. Such road density shall not exceed 0.25 miles per square mile, using the method known as the moving window method. 204. Applicability of title (a) Federal Land Management Agencies This title shall apply only to National Forest System lands and lands under the