The Environmental Protection Agency (EPA) is approving State Implementation Plan (SIP) revisions submitted by the State of Montana on March 17, 2010, August 1, 2011, November 22, 2011, and September 19, 2014. The revisions are to the Administrative Rules of Montana (ARM) and include minor editorial and grammatical changes, updates to citations and references to federal and state laws and regulations, revisions to open burning rules, changes to the process for appealing air quality permits, and providing a process for revocation of air quality permits when owners cannot be found by mail. Also in this action, EPA is correcting final rules pertaining to Montana's SIP. On January 29, 2010, EPA took direct final action to approve SIP revisions as submitted by the State of Montana on January 16, 2009 and May 4, 2009. EPA subsequently discovered an error in our January 29, 2010 direct final action related to "incorporation by reference" (IBR) materials and the associated regulatory text numbering. EPA is correcting this error with today's action. Finally, EPA is updating the Montana nonregulatory provisions table to add carbon monoxide maintenance plans for Billings, Montana, and Great Falls, Montana approved by EPA on March 30, 2015 and April 1, 2015, respectively. This action is being taken under section 110 of the Clean Air Act (CAA).