(a) On July 8, 1997, the Governor of Montana submitted revisions to the SIP narrative for the Missoula carbon monoxide control plan.
(b) Revisions to the Montana State Implementation Plan, revised Carbon Monoxide Maintenance Plan for Billings, as submitted by the Governor's Designee on July 13, 2011, and the associated Alternative Monitoring Strategy for Billings, as submitted by the Governor's Designee on June 22, 2012.
(c) Revisions to the Montana State Implementation Plan, revised Carbon Monoxide Maintenance Plan for Great Falls, as submitted by the Governor's Designee on July 13, 2011, and the associated Alternative Monitoring Strategy for Great Falls, as submitted by the Governor's Designee on June 22, 2012.
(d) Revisions to the Montana State Implementation Plan, Carbon Monoxide Redesignation Request and Maintenance Plan for Missoula, as approved by the Missoula City-County Air Pollution Control Board on January 20, 2005, by the Missoula County Commissioners on January 26, 2005 and by the Missoula City Council on March 7, 2005; and submitted by the Governor on May 27, 2005. [64 FR 68038, Dec. 6, 1999, as amended at 67 FR 7973, Feb. 21, 2002; 67 FR 31150, May 9, 2002; 72 FR 46161, Aug. 17, 2007; 80 FR 16573, Mar. 30, 2015; 80 FR 17333, Apr. 1, 2015]