Section 52.1339 - Visibility protection(a) The requirements of section 169A of the Clean Air Act are met because the plan includes measures for the protection visibility in mandatory Class I Federal areas. The Regional Haze Plan submitted by Missouri on August 5, 2009, and supplemented on January 30, 2012, in addition to the 5-year progress report submitted on September 5, 2014, and supplemented by state letter on July 31, 2017, contain fully approvable measures for meeting the requirements of the Regional Haze Rule.52 FR 45138, Nov. 24, 1987, as amended at 77 FR 33657 , June 7, 2012; 77 FR 38011 , June 26, 2012; 82 FR 3129 , Jan. 10, 2017; 83 FR 48244 , Sept. 24, 2018