Promulgating these federal regulations will address ozone-forming emissions from existing and new and modified oil and natural gas sources on Indian country lands within the Uintah and Ouray Indian Reservation (U&O Reservation) in Utah, portions of which are included in an area in the Uinta Basin that the EPA designated as nonattainment for the primary 2015 ozone national ambient air quality standard (NAAQS) for human health. The rulemaking seeks to achieve three goals for the Indian country portion of the Uinta Basin: (1) establish emissions control requirements for oil and natural gas activity that contribute to the Uinta Basin’s winter ozone problem; (2) establish regulatory requirements that are the same or consistent between Indian country and neighboring jurisdictions within the Basin; and (3) allow for reasonable continued development of the Basin’s oil and natural gas resources on the Indian country lands within the U&O Reservation that are included in the current Uinta Basin Ozone Nonattainment Area. This rule would apply to any person who owns or operates or plans to construct or modify an oil and natural gas facility on Indian country lands within the exterior boundaries of the U&O Reservation. The primary stakeholders are the oil and natural gas operators on the Reservation, the Ute Indian Tribe, State of Utah, and the public.