Colorado Bulk Transmission Environmental Review(9-CO)
In the state of Colorado, transmission lines are permitted at the local level. The Colorado Public Utilities Commission (PUC) has backstop authority only. If a permit is denied by the local government, the applicant may appeal to the PUC if certain conditions are met. 
Colorado does not have a state environmental review process as the siting of high-voltage transmission lines is typically done at the local level through the issuance of a 1041 Permit (used to regulate areas and activities of state interest), Conditional Use Permit, Special Use Permit, or other zoning and land use permits. However, environmental reviews/impact analysis may be required as part of the permit application process. For example, an environmental impact analysis is required as part of the 1041 application in Boulder County: Article 8: 8-507 Application Submittal Requirements. The applicant is required to identify potential environmental impacts as they relate to land use, water resources, wetlands and riparian areas, terrestrial and aquatic animals and habitat; terrestrial and aquatic plant life, air quality, recreation and open space, unique areas of geologic, historic and archaeologic importance; visual aesthetic resources.
Determine Which State and Federal Permits Apply
Use this overview flowchart and following steps to learn which federal and state permits apply to your projects.