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, where ambient ozone levels violate the 2015 ozone national ambient air quality standard (NAAQS) for human health. While the EPA currently provides for streamlined permitting of new and modified minor oil and natural gas sources in Indian country that applies nationally, that mechanism will no longer be available to such sources if the area is designated nonattainment for the 2015 ozone NAAQS and sources would need to obtain source-specific permits before beginning construction, potentially delaying continued development of oil and natural gas resources on the U&O Reservation. The rulemaking seeks to achieve three goals for the Indian country portion of the Uinta Basin: (1) clean air; (2) continued, uninterrupted development of the oil and natural gas resources; and (3) consistent CAA regulatory requirements between Indian country lands within the U&O Reservation and lands under State of Utah jurisdiction. 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, the State of Utah, and the public.