31. How are eligibility determinations made in Section 106 review? 

The regulations require the federal agency to apply the National Register eligibility criteria in consultation with the SHPO/THPO and any Indian tribe or NHO that attaches traditional religious and cultural significance to the property [36 CFR § 800.4(c)(1)]. During such consultation, a federal agency may use in-house expertise or rely on information and recommendations provided by applicants or consultants/contractors. The federal agency, however, is legally responsible for decisions on National Register eligibility.

Most eligibility determinations made within the Section 106 process are called “consensus determinations” because agreement between the federal agency and the SHPO/THPO is all that is required; no formal nomination to or listing on the National Register is necessary. Consensus determinations that properties are not eligible should also be documented so that consulting parties and the public have an adequate basis upon which to evaluate the agency decision.

When the federal agency and the SHPO/THPO disagree about eligibility, the opinion of the Keeper of the National Register must be sought [36 CFR § 800.4(c)(2)].  


32. What are the consequences of eligibility determinations in the Section 106 process?

The determination that an archaeological site is eligible for the National Register subjects it to Section 106 review.  This means the federal agency must then decide if the undertaking will alter that property’s qualifying characteristics, and if so, whether it will do so in a manner that will diminish the property’s integrity. If the agency determines there could be an adverse effect, then the agency consults further on appropriate measures to avoid, minimize, or mitigate that effect to the property.

In order to carry out these steps effectively, it is essential that the federal agency fully identify a property’s qualifying characteristics. To do so, the federal agency should explore the full range of National Register criteria that may apply to an archaeological site.

Frequently federal agencies just assume data recovery is the mitigation measure that should be automatically selected to resolve adverse effects to sites considered eligible solely under Criterion D. In fact, other measures, such as site burial, might be as appropriate. Given the inherent flexibility of the Section 106 process and its emphasis on resolution through consultation, a range of archaeological solutions usually should be considered.  


33. What special role do Indian tribes and Native Hawaiian organizations have in evaluating properties? 

The ACHP’s regulations acknowledge the special expertise that Indian tribes and NHOs possess in assessing the National Register eligibility of properties that may be of traditional religious and cultural significance to them [see 36 CFR § 800.4(c)(1)]. This means that the tribe’s or NHO’s opinions about, or position on, the National Register significance of a particular archaeological site as a property of traditional religious and cultural significance to that tribe or NHO should be given due consideration by the federal agency in making a final determination on eligibility.  


34. What kind of information is necessary to evaluate the eligibility of an archaeological site?

Archaeological sites often, but not always, require some limited exploration to gather information needed to make an evaluation. However, there is a distinction between “testing” archaeological properties for identification and evaluation and “excavating” them for purposes of data recovery.  Testing is aimed at determining if the site should be considered eligible for listing in the National Register. Generally, when testing an archaeological site, only a very small sample need be disturbed, but this varies on a case-by-case basis. While it is impossible to define a hard and fast standard, a rule of thumb is that testing is sufficient when enough is known about the nature, size, limits, and contents of the site to judge its significance and integrity against the National Register criteria.

Evaluation under each of the criteria should be done according to the professional standards of practice. The National Register Bulletin No. 36, “Guidelines for Evaluating and Registering Archeological Properties addresses the kinds of information needed to evaluate an archaeological site under the National Register criteria.  


35. Is a National Register nomination form required in a Section 106 evaluation of eligibility?

No. Section 106 eligibility determinations do not require filling out any National Register forms. However, the kinds of information called for in the forms, such as information on a property’s boundaries, area(s) and period(s) of significance, integrity, deposits, and National Register criteria being considered are essential to making eligibility determinations under Section 106.  


36. Is every archaeological site eligible for the National Register?

No. Not every archaeological site is eligible for the National Register because not all archaeological sites possess both significance and sufficient integrity to be considered eligible. Sites may be deemed important to a group or community, or people may feel that, as a place of ancestral occupation or activity these sites possess a value that should be recognized. However, in neither case does this automatically translate or equate to the requisite significance for National Register eligibility purposes.

To be eligible for listing on the National Register, archaeological sites must meet at least one of the four National Register criteria (A through D) established by the National Park Service and possess integrity. Significance relates to a historic property’s ability to meet at least one of the criteria. As with any other kind of historic property, listed or eligible archaeological sites must be associated with significant events (Criterion A), or be identifiable with specific, important individuals (Criterion B), be of a distinctive type or period or have artistic value, or be a component of an identifiable historic district (Criterion C), or “have yielded or have the potential to yield, information important in prehistory or history” (Criterion D, as quoted from the regulations). When determining significance under criterion D, one must keep in mind that while all archaeological sites can yield some kind of information, the key is to determine if that information is important. Importance is best assessed when considered within a framework of a historic context.

 Integrity is the ability of the property to convey significance through physical features and context. According to the National Register Bulletin No.36, Guidelines for Evaluating and Registering Archeological Properties”, integrity of location, design, materials, and association are of primary importance [for sites being considered] under Criteria A and B. Design, materials, and workmanship are especially important under Criterion C. Under Criteria C and D, integrity of setting adds to the overall integrity of an individual site and district.

For example, context, or the association of artifacts, features, and other site characteristics, is considered essential for the archaeological site to convey information about the past (Criterion D). The context of an archaeological site subjected to regular plowing or looting may be sufficiently disrupted so that the site no longer possesses integrity of association. On the other hand, for an archaeological site where a significant event took place (for example, consideration under Criterion A) integrity of feeling and setting may be more critical than association.

Consequently, a site with excellent associative integrity still may not be eligible if several other similar sites have already been studied, because the kind of information it could provide is considered redundant, and/or not currently important to history or prehistory. [For more detailed information about, and examples of, integrity refer to National Register Bulletin No. 36,Guidelines for Evaluating and Registering Archeological Properties” cited above].  


37. Can you evaluate archaeological sites under Criteria A through C in addition to D? 

Yes, it is possible for an archaeological site to be eligible under Criteria A, B, C, and D. The ACHP’s Section 106 regulations call for the federal agency to consider how all of the National Register qualifying characteristics of a historic property may be affected by the undertaking [36 CFR § 800.5(a)(1)]. Accordingly, when conducting its evaluation, a federal agency should determine the full range of criteria that may apply to a property. National Register Bulletin No. 36, “Guidelines for Evaluating and Registering Archeological Properties, lays out a step-by-step process for evaluating sites under all of the criteria and provides useful examples.  


38. Does the presence of human remains make an archaeological site eligible for the National Register?

Human remains, associated funerary objects, and the sites where they are found possess values beyond their importance as sources of information about the past. National Register Bulletin No. 36, “Guidelines for Evaluating and Registering Archeological Properties, also notes this distinction between an archaeological site’s National Register significance and other values it may exhibit. Therefore, Section 106 users should be aware that even when a property has been determined eligible for the National Register only under Criterion D, the special nature of burials, which are widely recognized in law and practice as having special qualities, may also possess a value to living groups that extends beyond the interests of archaeological research. Burial sites may be considered properties of traditional religious and cultural significance to Indian tribes or NHOs, which could make the site eligible for the National Register under more than simply Criterion D. See National Register Bulletin No. 41, “Guidelines for Evaluating and Registering Cemeteries and Burial Places” for further guidance.

For further direction in navigating the difficult and sensitive issues associated with the treatment of burial sites and human remains, see the ACHP’s “Policy Statement Regarding the Treatment of Burial Sites, Human Remains, and Funerary Objects”. 


39. When should an agency reevaluate the National Register status of archaeological sites?

According to the ACHP’s regulation, “[t]he passage of time, changing perceptions of significance, or incomplete prior evaluations may require the agency to reevaluate properties previously determined eligible or ineligible” [36 CFR § 800.4(c)(1)]. In deciding if reevaluation is warranted, a federal agency should consider the following questions, among others:

  • How long ago was the determination made?
  • Were Indian tribes or NHOs consulted about the eligibility of the archaeological site during the initial evaluation?
  • Have Indian tribes or NHOs been consulted to determine if the archaeological site may be of traditional religious and cultural significance to them?
  • What relevant physical changes to the archaeological site have occurred since the initial determination of eligibility was made?
  • Does the archaeological site still possess integrity?


40. Is the loss of access by archaeologists to listed or eligible archaeological sites an adverse effect under the ACHP’s regulations?

Some Section 106 stakeholders take the position that indefinite loss of access by archaeologists to known listed or eligible archaeological sites resulting from burial of the site under a road, parking lot, building, or other relatively permanent feature constitutes an adverse effect. They argue that since these historic properties will be unavailable for study indefinitely, the loss of access by archaeologists prevents a site that is eligible under Criterion D from yielding its  “information important in prehistory or history.” Some use this argument to support the notion that there is no limit to the depth of the area of potential effects. This argument concludes that federal agencies have an obligation under Section 106 to search for and evaluate deeply buried sites, even though such sites might lie below the depth of a particular undertaking’s APE. 

Such a position is not consistent with the ACHP’s Section 106 regulations, which state that an adverse effect occurs when: an undertaking may alter, directly or indirectly, any of the characteristics of a historic property that qualify the property for inclusion in the National Register of Historic Places in a manner that would diminish the integrity of the property’s location, design, setting, materials, workmanship, feeling, or association. [36 CFR § 800.5(a); emphasis added].

Accordingly, an action that will cause an adverse effect is one that will diminish an eligible or listed archaeological site’s integrity. Since loss of access by archaeologists for study is unlikely to alter the qualifying characteristics of a National Register listed or eligible archaeological site in such a way as to diminish that property’s integrity, it generally will not be considered an adverse effect by the ACHP.