The Secretary shall prepare, and may from time to time amend, a management plan for the national recreation area. The plan may be prepared in conjunction with, or incorporated with, ongoing planning for the Allegheny National Forest in accordance with the National Forest Management Act of 1976. The initial management plan and significant amendments or revisions shall be accompanied by an environmental impact statement prepared in accordance with the National Environmental Policy Act of 1969 [
42 U.S.C.
4321 et seq.].