National Environmental Policy Act Process

The National Environmental Policy Act (NEPA) process looks at:

social impacts, such as:

  • land use;
  • community facilities;
  • noise; and
  • air quality.

economic impacts

impacts to environmental resources, such as:

  • wildlife;
  • water resources;
  • parks;
  • historic resources;
  • aesthetic conditions; and
  • water quality.

The process includes public and agency involvement and development of alternatives.

The study area is covered in a federal decision document called a Tier 1 Record of Decision, a high-level NEPA document that identifies transportation improvements (capacity, mode, and location) to be made along the I-70 mountain corridor between C-470 and Glenwood Springs. These improvements must be studied in more detail in project-specific Tier 2 NEPA processes. Other Tier 2 NEPA documents that have been prepared in this area include:

Contact Us

The I-70 Mountain corridor is a magnificent, scenic place in close proximity to the Denver Metro area. Human elements are woven through breathtaking natural features. The integration of these diverse elements has occurred over the course of time. The corridor is a recreational destination for the world, a route for interstate and local commerce and a unique place to live.

I-70 is also federally designated as a high-priority corridor, a significant part of the defense network, a major east/west continental corridor and a major economic corridor for Colorado. For many local communities along the corridor, I-70 is the lifeline, primary access and only connection to other communities.

Current I-70 roadway geometry is constrained with narrow shoulders and tight curves that impact safety, mobility, accessibility, and capacity for travelers and residents. In a manner that respects the unique environmental, historic, community and recreational resources in Clear Creek County, westbound improvements are needed to lessen delays caused by peak period volumes.


Colorado: The Official State Web Portal