; or (C) alters the authority of the State— (i) to maintain the access road to the crest of Shenandoah Mountain (Route 924); or (ii) to realign the access road described in clause (i) if necessary for reasons of sound resource management or public safety. (4) Parking areas (A) In general Subject to subparagraph (B), the reconstruction, minor relocation, and construction of parking areas and related facilities within the National Scenic Area are authorized in a manner consistent with the purposes of the National Scenic Area described in subsection (b). (B) Limitation Additional trailhead parking areas authorized in the National Scenic Area under subparagraph (A) may be constructed only along National Forest System roads. (g) Motorized travel Motorized travel shall be allowed only on roads within the portions of the National Scenic Area that are not Wilderness Areas, in a manner consistent with subsection (f). (h) Water The Secretary shall administer the National Scenic Area in a manner that maintains and enhances water quality. (i) Water impoundments The establishment of the National Scenic Area shall not prohibit— (1) the operation, maintenance, or improvement of, or access to, dams, reservoirs, or related infrastructure in existence on the date of enactment of this Act, as generally depicted on the map filed under section 5(a)(1); or (2) the establishment of new dams, reservoirs, or related infrastructure if necessary for municipal use. (j) Timber harvest (1) In general Except as provided in paragraph (2), no harvesting of timber shall be allowed within the National Scenic Area. (2) Exceptions (A) Necessary harvesting The Secretary may authorize harvesting of timber in the National Scenic Area if the Secretary determines that the harvesting is necessary— (i) to control fire; (ii) to provide for public safety or trail access; (iii) to construct or maintain overlooks and vistas