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Case Study - Colorado

Programmatic Agreement Developed for the Tier 1 EIS, Interstate-70 Mountain Corridor

Description of Undertaking

Western Colorado’s Interstate 70 is the major east-west corridor between Denver and many Colorado mountain communities and ski areas. The Federal Highway Administration (FHWA) and the Colorado Department of Transportation (CDOT) are considering options for increasing capacity and reducing congestion on this heavily traveled mountain corridor.  The study area includes some 144 miles of Interstate 70, which cuts through five counties and stretches from Denver to mountain communities and ski areas in western Colorado. FHWA is conducting a tiered environmental review process for the undertaking.

The first tier is development of a Programmatic Environmental Impact Statement (PEIS) and Record of Decision (ROD) that selects a transportation mode (or modes) for future improvements along the I-70 Mountain corridor over the next 50 years. As a result of coordination of Section 106 and NEPA for this project, the Final Tier I PEIS will include a separate section summarizing and evaluating the relative effects of the undertaking on historic properties, reflecting input from the consulting parties. Tier 2 will be the development of additional, more detailed environmental review documents for the design and construction of individual segments of the 144 mile-long corridor.

For additional information see Case Digest articles at (Summer 2005) and (Spring 2007).

Historic Properties and Effects

The existing highway cuts through several historic mountain communities, including the Georgetown-Silver Plume National Historic Landmark District, which includes 384 individual historic properties and the Georgetown Loop railroad grade that runs between the towns of Georgetown and Silver Plume and was considered an engineering marvel of the late 19th century.  I-70 also goes through the Idaho Springs Commercial District and the Hot Springs Historic District in Glenwood Springs, which was developed between the 1880s and early 1900s as a resort. In addition, the I-70 corridor mountain communities in Clear Creek County are historically significant for their association with the development of the mining industry in Colorado. The alternatives under consideration for the Tier 1 PEIS are all contained within the existing I-70 right-of-way. A Preliminary EIS was published for public comment in December 2004, and FHWA and CDOT anticipate reaching a decision on the project that may include a combination of increased traffic lanes or increased rail or bus service. Any of the alternatives under consideration will likely have direct impacts on some historic buildings and structures, as well as noise and visual effects on the historic districts. There are no known impacts to archaeological properties or Native American traditional cultural properties.

Analysis of Consultation and Agreement

FHWA and the Colorado Department of Transportation (CDOT) initiated consultation to develop a Programmatic Agreement (PA) with the State Historic Preservation Office (SHPO) and ACHP in January 2005. Eventually, 19 signatories and consulting parties were identified, including the local governments and historic preservation organizations from the affected historic communities (see list below). After a rough start, CDOT hired a consultant to facilitate Section 106 consultation and develop the Section 106 Programmatic Agreement (PA). Interviews with individual consulting parties and two consultation meetings with all parties (listed below) served to identify issues to be addressed in the PA.  A final draft PA was completed in February 2006, but execution of the agreement was postponed until 2008 because of a delay in publication of the Final PEIS for the project.  

Throughout consultation, local governments and historic preservation organizations in the historic mining towns remained concerned that the most likely alternative, adding traffic lanes to I-70, would further contribute to increased traffic and noise pollution. These organizations strongly supported a multi-modal solution to the project, whose purpose is to reduce traffic congestion and increase capacity between Denver and popular recreation areas (including ski areas) along the corridor. In October 2007, CDOT invited of 27 stakeholders to work with an independent facilitator to find a preferred alternative that best meets the needs of local governments, highway users, transit, environmental, business and recreation interests, as well as state and federal agencies. The “Collaborative Effort” stakeholders group, which includes a representative of the historic preservation community, is close to reaching an agreement on a vision and specific recommendations for Tier 1: a multi-modal solution that includes non-infrastructure components, a commitment to evaluation and implementation of an Advanced Guideway System, and highway improvements. The Section 106 Programmatic Agreement (PA) establishes a process for consultation during Tier 2 undertakings, regardless of which alternative is selected in Tier 1.

What’s unusual about the consultation process is that FHWA and CDOT have used a collaborative process to reach consensus among many stakeholders on the mode of transportation to be pursued in future smaller developments along the route. Additionally, unusual is the fact that FHWA and CDOT developed a PA addressing both Tier I and Tier 2 of a tiered NEPA (National Environmental Policy Act) review process in a manner that provides for the comprehensive consideration of direct effects as well as indirect and cumulative effects of the project on historic properties. Direct physical impacts will be minimal, as all alternatives are within the existing right-of-way. The primary concern to consulting parties and the focus of the PA and PEIS are noise impacts, visual effects, and the cumulative effects of increased traffic on the economic viability of their communities as heritage tourism sites.  

This PA should serve as an excellent model for early coordination of Section 106 and NEPA; and for completing Section 106 on large transportation projects involving tiered environmental documents. The PA includes a number of innovative measures to mitigate the effects of the project on historic properties. The final PA commits FHWA and CDOT to:

  • plan, design, and implement the Tier 2 undertakings in accordance with the principles of Context-Sensitive Solutions (CSS);
  • develop a historic context or contexts for the Mountain Corridor prior to implementing any Tier 2 undertakings;
  • carry out consultation with the Section 106 consulting parties in designing Tier 2 undertakings, including a commitment to take into account direct, indirect, and cumulative effects on historic properties including measures to improve existing conditions affecting historic properties;
  • follow negotiated guidelines incorporated into the PA for assessing physical, visual, noise, and economic impacts of Tier 2 undertakings on the historic districts; and
  • provide support for historic preservation efforts in the towns of Georgetown, Silver Plume, and Idaho Springs including assistance in identification and evaluation National Register districts and evaluating contributing structures to existing districts beyond the area expected to be directly impacted by the project. 

Although no archaeological properties were identified during a cultural resources inventory of the project right-of-way, the PA also provides for additional identification efforts in Tier 2. In separate consultations with Indian tribes having historic ties to the project area, FHWA and CDOT executed a PA with the tribes establishing protocols for tribal consultation on Tier 2 undertakings. The tribal agreement has been incorporated into the enclosed PA as Appendix D.

The PA was executed on April 3, 2008; signed by all six signatories and most of the concurring parties listed below.  

PA Signatories

  • ACHP
  • Federal Highway Administration
  • US Forest Service, Rocky Mountain Region
  • BLM, Glenwood Springs Field Office
  • Colorado SHPO
  • Colorado Department of Transportation

Parties Invited to Concur in the PA 

  • Clear Creek County
  • Eagle County
  • City of Glenwood Springs
  • Town of Georgetown
  • Town of Silver Plume
  • Georgetown Silver Plume Historic District Public Lands Commission
  • National Park Service, Intermountain Region
  • Colorado Preservation, Inc.
  • National Trust for Historic Preservation Mountain Plans Office
  • Colorado Historical Society
  • Historic Georgetown, Inc.
  • The Historical Society of Idaho Springs
  • Mill Creek Valley Historical Society

Lessons Learned

  • Initiate consultation early to avoid conflict. Much of the initial consultation on the Section 106 PA was stymied by the belief among consulting parties that CDOT had eliminated viable alternatives for the project before engaging the historic preservation community in consultation. 
  • Use of a third party facilitator can improve the consultation process where consulting parties distrust the process. CDOT used a third party facilitator from the SRI Foundation to manage consultation under Section 106 and develop the PA. It also found use of a third party facilitator effective in resolving broader stakeholder concerns with the environmental review process under NEPA.
  • A programmatic agreement for long term Tiered EIS transportation projects provides an excellent tool for collaboration and documenting agreement among consulting parties on principles and procedures for future review. The I-70 PA is a particularly good example, as it provides the consulting parties with some very specific mitigation measures that go beyond the minimum standard. It also benefits CDOT in streamlining the completion and documentation of Section 106 review for Tier 2 undertakings.

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Updated June 1, 2009

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