Air quality remains one of the most dynamic and legally complex areas of environmental regulation affecting the oil and gas industry. The evolving regulatory landscape continues to generate significant uncertainty for regulated entities, state agencies, Tribal governments, environmental specialists, and legal practitioners alike. With numerous federal rules under formal reconsideration and new enforcement approaches emerging, stakeholders must navigate a constantly shifting terrain of compliance obligations and risk mitigation strategies. At the same time, state governments and environmental organizations continue to assert leadership through litigation and localized regulatory innovation, particularly in areas where federal oversight has receded.