Cultural Resources

The Bureau of Reclamation is committed to preserving historical and archaeological sites as required by the National Historic Preservation Act (NHPA). The NHPA created the National Register of Historic Places (NRHP) and the list of National Historic Landmarks (NHL). The NHPA also allowed for the formation of State Historic Preservation Offices (SHPO) to play critical roles in carrying out historic preservation.

Section 106 of the NHPA requires Federal agencies to take into account the potential effects of a proposed Federal undertaking on historic properties. Historic properties are any prehistoric or historic district, site, building, structure or object included in, or eligible for inclusion in, the NRHP. Federal agencies consult with the SHPO to determine whether or not a cultural resource is eligible for listing in the NRHP, and the effect the proposed Federal undertaking may have on eligible properties.

Historical and archaeological sites are termed “cultural resources.” Cultural resources are defined as physical or other expressions of human activity or occupation. Cultural resources are evaluated for significance in terms of NRHP eligibility. The significant criteria applied to evaluate cultural resources are defined as the quality of significance in American history, buildings, structures and objects that possess integrity of location, design, setting, materials, workmanship, feeling, association and:

  1. That are associated with events that have made a significant contribution to the broad patterns of our history; or
  2. That are associated with the lives of persons significant in our past; or
  3. That embody the distinctive characteristics of a type, period, or method of construction, or that represent the work of a master, or that possess high artistic values, or that represent a significant and distinguishable entity whose components may lack individual distinction; or
  4. That have yielded, or may be likely to yield, information important in prehistory or history.

When a Federal undertaking will have an adverse effect on cultural resources which are eligible for listing in the NRHP, the Federal agency coordinates with the SHPO to determine appropriate measures the agency will take to mitigate the adverse effect. A common form of mitigation is documentation of the cultural resource on archival materials. There are three levels of documentation, as described in “Historic Resource Documentation, Standards for Level I, II and III Documentation” (Office of Archaeology and Historic Preservation Publication 1595, March 2013).

The Colorado SHPO retains copies of the mitigation documentation in their archives, however these materials are not easily accessible by the general public. In an effort to increase the public benefit of these reports, Reclamation has developed this webpage to provide public access to documentation of cultural resources effected by Reclamation’s undertakings.


  • Summary Report of the Level I Documentation of the Cattleman's Ditch, Montrose County, Colorado
  • Summary Report of the Level I Documentation of the Duke Ditch, Delta County, Colorado
  • Summary Report of the Level I Documentation of the Orchard Ranch Ditch, Delta County, Colorado
  • Summary Report of the Level I Documentation of Segments of the Grand Valley Canal, Mesa County, Colorado
  • Last Updated: 8/7/17