Consultation Guidance

The following is the Revised Consultation Guidance for Section 106 from the Colorado Office of Archaeology and Historic Preservation.

A PDF of this page is available to download.


The Office of Archaeology and Historic Preservation (OAHP) is a division of History Colorado (The Colorado Historical Society) and serves as the Colorado State Historic Preservation Office (SHPO).

Federal agencies are required to engage in what is termed “consultation” with the SHPO to determine if any Federally funded or permitted activities may have an adverse effect on historic properties.  Historic properties include not only those properties that are officially listed on the National Register of Historic Places, but also those that are determined to be eligible for the National Register.  This requirement is set forth in Federal legislation known as the National Historic Preservation Act.  The consultation process is described in Section 106 of that act.

Sometimes Federal agencies will delegate to its grantees or permitees the job of consulting with the SHPO in the Section 106 consultation process.  This guide is designed to help those who are unfamiliar with the Section 106 consultation process both understand what the process is and how to provide to the SHPO information needed to respond to a request without our office having to request additional information from you.

For an overview of the Section 106 review process, you may wish to read A Citizens Guide to Section 106 Review, a short publication found on the ACHP web site.

A list of properties currently on the National Register in Colorado can be found on our website.  In addition, our office maintains a library of many thousands of inventory forms for properties already recorded.  It may be possible to determine if the property or properties involved with your project has/have already received determinations regarding whether they are eligible to be listed on the National Register.  This process is called a “File Search” for which there may be a small fee depending on how much research is required.  Therefore your next step may be to contact our office to determine if this is the case.

For more information on file searches, please contact the SHPO at (303) 866-5216 or visit our file search page on this web site.


The following guidance is intended to be a guide to the information that the SHPO may need to respond to your Section 106 consultation request.

  1. Project description
    1. Identify the Federal agency involved, the agency program and type of Federal involvement
      • Example 1:   The Federal agency involved is the Department of Housing and Urban Development (HUD) the staff contact information for which is ___________; the Federal program is CDBG; and the type of Federal program is a low-interest loan to conduct rehabilitation work on downtown buildings.
      • Example 2:   The Federal agency involved is US Department of Agriculture Rural Development the staff contact information for which is ___________; the Federal program is the rural solar program; and the type of Federal program is a grant to fund a portion of the costs to place solar panels on a barn.
      • Example 3:   The Federal agency involved is the Department of Energy the staff contact information for which is ___________; the Federal program is rural electrification; and the type of Federal program is permitting transmission lines.
    2. What do you propose to do?
      • Example 1:   Remove metal siding on several buildings; repair façade materials in need of repair; and paint.
      • Example 2:   Install solar panels on the south side of a barn.
      • Example 3:   With heavy machinery construct towers and string lines that may be seen for hundreds of feet in any direction.
    3. Provide vicinity information
      1. Are there any buildings or structures 50 or more years of age on or adjacent to property site?
        (This is important because 50 years is the established age to begin to evaluate if a building is eligible for listing on the National Register and will require research with the county assessor.)
      2. Will any buildings 50 or more years of age be vacated elsewhere as a result of this project?
        (This is important because abandonment of a building eligible to be listed on the National Register may be considered an adverse effect to the building.)
      3. Will there be any ground disturbance?
        (This is important to determine if archaeological sites may be affected by the project.)
        1. Has the land been previously disturbed?
        2. Will access roads be constructed?
        3. Will the project require borrow areas?
        4. Will the project require staging or storage areas?
      4. What are the previous use(s) of site?
        (This is important to determine if previous uses may have damaged properties or obliterated archaeological sites.)
  2. Establish the Area of Potential Effect (APE), which is defined as the geographic area or areas within which an undertaking or project may cause changes in the character or use of historic properties, if such properties exist.  The APE should reflect the potential visual, auditory and physical effects to the setting of historic resources
    • Example 1:   The APE of a project to do interior work may be only the building involved. However the APE for exterior work may also include the neighborhood if the neighborhood may be eligible or listed as a historic district.
    • Example 2:   The APE for a tall structure (such as a barn) may include the area in which it is visible if there are eligible properties for which the viewshed is part of their significance.
    • Example 3:   The APE will include the areas of the ground that will be used for construction, staging, and building access roads.  In addition, because the electrical towers will be seen for hundreds of feet in any direction, the APE may include all or part of the area in which they are visible (similar to Example 2).
  3. Complete Inventory form(s) for each building or structure (50+ years old) and archaeological site within the APE.  The inventory form should include your opinion on the National Register-eligibility of any resource for which an inventory form is completed.  The form that is used for a building is called the Architectural Inventory Form 1403 and is available on our website.  There are other forms for archaeological sites and linear resources (such as railroads or ditches) for which you are best advised to hire a consultant to complete.  Inventory forms may be found on our website.
  4. Federal regulations state that the federal agency should supply its opinion on the project’s  potential effects to resources identified as eligible for the National Register within the APE.  If the federal agency has delegated this to you and you do not have the expertise to do it, you will have to rely upon the SHPO’s determinations.  The types of effects are:
    1. No historic properties affected
      This finding of effect is appropriate when there are no National Register-listed or eligible properties within the APE, or if there are such properties they will not be affected by the project.
    2. No adverse effect
      This finding of effect is appropriate when the project will affect a National Register-listed or eligible property but the effect will not diminish the characteristics rendering a property eligible for the National Register.
    3. Adverse effect
      This finding of effect is appropriate when the project will diminish the characteristics rendering a property eligible for the National Register—either completely (for example, by demolishing it), or significantly (for example, by altering the façade of a building).
  5. Consult with the appropriate local government and other consulting parties regarding your determinations of eligibility and potential effects, if applicable.  The local government in which your project is located is required to be given the opportunity to offer its opinions on the project.  Therefore you should also forward your request to the local government as well as the SHPO.  Many local governments have their own historic preservation ordinance.  A list of these local governments is on our website.

    In addition, Native American tribes are required to be notified depending on the nature of the project.  This is particularly important in rural areas or for projects where ground disturbance will take place.  The applicable federal agency remains responsible to conduct this consultation.

    For more information on consulting party requirements, you should contact the SHPO.

Correspondence with our office should be addressed to:

Dawn DiPrince
State Historic Preservation Officer
History Colorado
1200 Broadway
Denver, CO 80203