To amend part C of title I of the Clean Air Act to improve air quality, and for other purposes.

Amends the Clean Air Act to add national historical parks to the list of areas which may be redesignated only as class I or II areas. Provides that national wilderness areas exceeding 5,000 acres and national parks exceeding 6,000 acres may be redesignated only as class I or II areas. (Current law permits such areas in excess of 10,000 acres to be redesignated as class I or II areas.)

Requires States in which class II national monuments, primitive areas, preserves, recreation areas, wild and scenic rivers, wildlife refuges, lakeshores, seashores, historical parks, parks, or wilderness areas are located and the Indian tribes with jurisdiction over such lands to reclassify such areas as class I unless a determination to retain the class II classification is made. Applies specified preconstruction and permit notification requirements with respect to the operation of proposed facilities in class I areas to such national areas.

Prohibits the issuance of permits to any facility unless the owner or operator demonstrates that emissions of any air pollutant for which maximum allowable increases are in effect under the Clean Air Act (Currently, particulate matter and sulfur dioxide) will not cause concentrations exceeding such increases for a class I area.

Directs the Administrator of the Environmental Protection Agency to promulgate regulations to assure that visibility requirements for class I areas are met with respect to regional haze. Provides for revisions to State implementation plans to incorporate such requirements. Requires the Administrator to review periodically the status of visibility impairment in class I areas and determine whether reasonable progress toward the national goal is being achieved.

Directs the Administrator to study and report to the Congress on the impact of uncontrolled fossil-fuel fired power plants on the air quality related values of class I areas located within 100 miles of such plants. Authorizes the Administrator to require continuous emissions monitors for sulfur oxides and nitrogen oxides to be installed at such plants.

Permits the Administrator, if the interstate transport of air pollution may cause manmade visibility impairment or adverse air quality in protected Federal areas, to establish a multi-State commission to study the impact of such air pollution and specify requirements for implementation plans to end the adverse impacts. Provides for the revision of State plans when the Administrator or the commission makes final findings on such impacts.

Requires the Administrator to establish a commission to address visibility impairment and other air quality related impacts in the Grand Canyon National Park.