The Environmental Protection Agency (EPA) is taking direct final action to approve State Implementation Plan (SIP) revisions submitted by the state of Montana on September 8, 2016. The revisions are to the Administrative Rules of Montana (ARM) and include updates to the citations and references to federal and state laws and regulations, updated links to sources of information, and provides clarity on how copies of federal regulations may be obtained. This action is being taken in accordance with section 110 of the Clean Air Act (CAA).