Archaeological / Cultural Resources Assessment

Natural Investigations cultural resources specialists provide a wide range of services to help clients achieve compliance with federal, state, and local regulations. We specialize in compliance with the California Environmental Quality Act (CEQA), the National Historic Preservation Act of 1966, the Archaeological Resources Protection Act of 1979, the Native American Graves Protection and Repatriation Act of 1990, as well as the cultural resources requirements of NEPA, and various state and local regulations and statutes. During the life of a project, we routinely consult with the appropriate federal, state or local regulatory agencies, local Native American tribes, preservation groups and historical societies, to name a few, to ensure all compliance, agency guidelines, and local interest issues are met.

Cultural Resources Surveys

The purpose of a survey is to identify the cultural resources in an area, usually by a pedestrian examination of the entire project area, or a sample portion of a study area, or a more intensive survey of a previously recorded site. Natural Investigations may design a mixed survey strategy incorporating both judgmental and random sample units. Judgmental units would be focused on areas with known but unrecorded cultural resources and other areas with a high probability for cultural resources. Natural Investigations would develop a predictive model to guide selection of probabilistic sample units. The strategy would also feature stratified, randomly selected sample units. Previously surveyed areas and previously recorded resources would be excluded from the randomly selected sample units. Sample units may be configured to any shape or size.

Archaeological surveys would typically include a literature search from the California Historical Information System, archival research, review of available aerial photographs, consultation with local Native American tribes known to be historically located in the geographical region, and a Sacred Lands Search from the Native American Heritage Commission (NAHC). A historic resources survey would typically include archival research, resource surveys of historic buildings, historical overviews, preservation plans, interpretive plans, National Register nominations, and evaluation of historical archaeological sites.

Pedestrian reconnaissance would record all new or previously known resources (e.g., built historic period, archaeological sites, isolates), including GPS locations, and preparation of Department of Parks and Recreation series 523 site forms. Digital photos would be taken of the general project area as well as the cultural resources, potential features, temporally diagnostic artifacts or other chronological indicators, isolated occurrences, architectural characteristics, building materials, or additional relevant items. Fieldwork would include recordation, description, digital photography, mapping, and/or sketching of all identified cultural resources. Any sites, built historic resources, features, isolated occurrences, or items of interest would be recorded with a handheld GPS unit for location data. GIS software would be used to create high-quality digital maps for the site records. Recordation would likely include an estimate of the age of the resource, depending on the nature of the artifacts present. At the end of the project, Natural Investigations would complete a comprehensive technical report, including all background information and following ARMR standards.

Evaluate Resources for Eligibility in the CRHR and/or NRHP

Our team has the requisite experience to efficiently and accurately evaluate built environment properties, historic archaeological sites, prehistoric archaeological sites, and Traditional Cultural Properties (TCPs), based on data gathered on both the built environment and archaeological resources. In order to thoroughly evaluate archaeological and historic period resources for eligibility for listing in the CRHR and/or the NRHP, Natural Investigations would gather all the data needed to adequately document and evaluate each resource in light of criteria listed in the revised CEQA Guidelines [Section 15064.5(a)(3)(A-D)] and/or National Register criteria delineated at 36 CFR 60.4. As a subset of historic properties subject to NHPA guidelines and regulations, including Section 106, TCPs would also be evaluated based on National Register Bulletin 38: Guidelines for Evaluating and Documenting Traditional Cultural Properties.

Natural Investigations would prepare a detailed, site-specific Work Plan for each resource. All prior work would need to be reviewed and evaluated to determine which resources would require additional research. In general, such a plan would initially include a review of the adequacy of existing recordation (e.g., DPR forms, GIS, mapping, catalogs, photographs, drawings, feature plans, and feature profiles), and an assessment of whether supplemental archival or oral history materials would need to be gathered in order to adequately interpret each historic period or archaeological resource. The Work Plan would include a Research Design specific to the area and based upon historic, ethnographic, and archaeological data. All components of the research design, including theoretical, research questions, data requirements, and methods, would be well integrated. The Research Design would indicate the Principal Investigator’s theoretical perspective, or rationale; provide an appropriate context for the area under study and identify regional research domains; propose specific research questions and cultural themes (and appropriate data requirements) to be addressed; and describe data collection and analytical methods employed to achieve objectives of the research. If further information were necessary to determine eligibility, we would next determine the type of testing and/or research required to determine whether the resource has integrity and if it is has the potential to yield information important in history and/or prehistory.

Depending on the resource, the type of testing and/or research required may include metal detection, fiberglass probe, surface clearing, mapping, excavation, surface scrapes, shovel test pits, feature recordation, photo documentation, etc., as deemed appropriate for each resource. For built historic resources (e.g., buildings, structures, engineering features), collection of supplemental archival or oral history materials, complemented by full recordation of the resources (e.g., DPR forms, photographs, drawings) may be sufficient for interpretation and evaluation of CRHR/NRHP eligibility. For TCPs, interpretation and evaluation of eligibility would likely require supplemental documentation from ethnohistoric and/or oral history, as well as Native American consultation. For a prehistoric or historic archaeological site, additional measures would include a Testing Plan, prepared in accordance with the Guidelines for Archaeological Research Designs by the California OHP. The Testing Plan would outline the background, research approach and methods to be used to guide the test excavation.

Evaluation-level documentation of an archaeological site would require only enough excavation to determine if the resource has integrity and data potential. Surface scrape units (SSUs), for example, would be used to define the horizontal extent of a site, and provide information concerning surface artifact density and distribution. Subsurface testing by shovel test pits (STPs) or test excavation units (TEUs) would be completed to determine if there is an archaeological deposit and, if so, to determine its vertical extent. If excavation were deemed appropriate, 1 × 1 meter TEUs would be placed to determine site boundaries (vertical and horizontal extents), record subsurface features in stratigraphic (if present) or arbitrary levels, and address site formation processes, as needed. Artifacts would be catalogued in the field and either left in place or collected, as specified in the Research Design for that resource. As part of the Testing Plan, Natural Investigations may recommend the collection and analysis of special samples (e.g., pollen, protein residue, radiocarbon dating, obsidian sourcing, hydration) in order to adequately document the value of the resource. All material (artifacts and ecofacts) would be systematically collected and analyzed in order to adequately address and answer the series of research questions posed in the Testing Plan. Natural Investigations would recommend curation of any cultural materials collected from the investigations at an appropriate facility that meets the curatorial standards set forth at 36 CFR 79, pursuant to the NHPA, Section 101 (a)(7)(A).

The results of the evaluation would be presented in a detailed technical report addressing the research questions and assessing the CRHR and/or the NRHP eligibility of the archaeological resource. The report would include full recordation and documentation of the fieldwork and the resource DPR forms. Resource condition, integrity considerations, and management recommendations would also be noted. All resources would be recorded and mapped to SHPO standards. Management recommendations may include that a qualified archaeologist monitor any future ground disturbing activity in native soils or sediments during any proposed development of the area and that the monitoring archaeologist must be empowered to temporarily divert grading equipment in the event of a discovery and allow for sufficient time to evaluate and potentially remove the find(s). The report would follow the Archaeological Resource Management Reports (ARMR): Recommended Contents and Format guidelines developed by the California OHP.

Should human burials be discovered during field investigations, Natural Investigations would follow the procedures of conduct mandated by Section 7050.5 of the California Health and Safety Code; or, if on federal land, under the provisions of the Archaeological Resources Protection Act (ARPA) and the Native American Graves Protection and Repatriation Act (NAGPRA).

Mitigation and Treatment Measures

Natural Investigations has an experienced team that recommends appropriate mitigation and treatment measures for each cultural resource, including archaeological sites, TCPs, and built historic resources (e.g., buildings, structures, and engineering features). After completion of comprehensive background research, Natural Investigations would develop a Work Plan to determine the significance of the resource, and any necessary mitigation measures consistent with CEQA Guidelines Section 15126.4(b) and/or NHPA Section 106. For prehistoric or historic archaeological sites, such mitigation measures may include test excavations to assess subsurface integrity.

Presuming the cultural resource under investigation is found to be a significant prehistoric or historic archaeological site that qualifies as a “historic property” and as a “historical resource” eligible for listing in the NRHP and CRHP, Natural Investigations would recommend treatment options. The preferred mitigation of impacts to archaeological sites is preservation in place. If this cannot be accomplished through avoidance, incorporation within parks or open space, covering with a layer of sterile soil, deeding into a permanent conservation easement, or similar measures, then Natural Investigations would prepare an adequate Data Recovery Plan, to be adopted prior to the start of a scientifically controlled removal, and collection. Excavation studies would be more detailed than for an evaluation of the integrity and data potential of a resource. A report of the completed study, in ARMR format, would be deposited with CHRIS and any relevant agency. Any human remains encountered would be treated in accordance with the provisions of Section 7050.5 of the Health and Safety Code; or, if on federal land, under the provisions of ARPA and NAGPRA. In addition, curation of artifacts removed during excavation or testing may be an appropriate mitigation, and Natural Investigations would recommend curation at an appropriate facility that meets the curatorial standards set forth at 36CFR79, pursuant to the NHPA, Section 101 (a)(7)(A).

For TCPs that have been determined to be eligible for listing, Natural Investigations would recommend treatment options consistent with CEQA Guidelines Section 15126.4(b), as well as consultation with the local Native American groups. Preferred mitigation is avoidance and protection. If this cannot be accomplished, consultation would be recommended as part of determining alternate mitigation steps.

For built historic resources (e.g., buildings, structures, engineering features), presuming the historic-era resource under investigation qualifies as a “historic property” and “historical resource” eligible for listing in the NRHP and CRHP, respectively, Natural Investigations would recommend treatment options consistent with CEQA Guidelines Section 15126.4(b). Preferred mitigation is avoidance and protection of the historic properties through re-routing roads, changing land use patterns, fencing, gating access roads, etc. Alternate mitigation recommendations by Natural Investigations for built resources would be to maintain, repair, stabilize, rehabilitate, restore, preserve, conserve, or reconstruct the historic resource in a manner consistent with the Secretary of the Interior’s Standards for the Treatment of Historic Properties with Guidelines for Preserving, Rehabilitating, Restoring, and Reconstructing Historic Buildings. Alternately, depending on the circumstances, documentation of the historical resource may be recommended to mitigate any effects of demolition. Documentation may include full recordation on DPR forms, photographs, architectural drawings, or a historic narrative. We would recommend that this type of information be provided to the public; for example, by dissemination of an article or booklet or filing with local libraries or museums. If needed, we would also negotiate preservation strategies or data recovery of any historic structures using Historic American Buildings Survey/Historic Architectural Engineering Record (HABS/HAER) forms through the OHP and the National Park Service (NPS).

Technical Reports and Environmental Impact Report (EIR) Sections

Natural Investigations would prepare comprehensive cultural resources technical reports documenting the results of all work completed under provisions of Section 106 of the NHPA and/or CEQA. The report would include the background prehistoric and historic context for the area, cultural affiliations, any previous archaeological research, any Native American consultation and/or monitoring; discussion and presentation of a Research Design or Testing Plan (if applicable); all methods and results; details for each site; any special studies; synthesis of the findings within a regional framework; and an analysis summary. The report would also identify observed disturbances or threats to cultural resource integrity, and contain management recommendations, including possible directions for future research.

The report may include a CRHR and/or NRHP eligibility discussion and/or a formal evaluation of each site or built feature in accordance with CEQA guidelines and 36 CFR 800.4. We would also provide an assessment of effects of a proposed project to properties that are recommended eligible in accordance with 36 CFR 800.5. In sum, the data collected and reported would be sufficient to allow the lead agency to determine if the resource is eligible for listing on the CRHR and/or the NRHP.

The format of the technical report would follow the Archaeological Resource Management Reports: Recommended Contents and Format guidelines developed by the OHP. The report would include, as appropriate, photographs and several figures, including a project overview map and a site map depicting the location of any testing. Appendices may include new or updated DPR site forms and/or HABS/HAER forms, catalogs, the original reports received from special studies analysts, and Native American report, etc. All references would be appropriately cited using the latest American Antiquity style guide.

Natural Investigations’ team of cultural resources experts includes professionals with the experience and expertise to turn technical reports into EIR sections and to evaluate existing technical reports and determine what additional information may be required for compliance under CEQA guidelines. For the preparation of EIR sections, adequate methods used to evaluate cultural resources typically include background research (e.g., record searches, literature review, and archival research), the prehistoric and historic context for the area, cultural affiliations, pedestrian survey, and recordation of resources on DPR forms. Natural Investigations would weigh the results of these investigations to determine if a project has the potential to cause a substantial adverse effect to the recorded resources, and if the impact is potentially significant. This assessment would then form the basis of preferred or recommended mitigation measures, consistent with CEQA Guidelines Section 15126.4(b).

Agency and Native American Consultation

Our qualified staff would be available for consultation with appropriate agencies, Native American tribes, or other interested parties. Natural Investigations staff have decades of experience consulting on cultural resources projects with federal, state, and local agencies, including OHP, SHPO, Federal Energy Regulatory Commission, U.S. Forest Service, U.S. Bureau of Reclamation, Bureau of Land Management, and NPS.

Natural Investigations would contact the Native American Heritage Commission (NAHC), per NHPA Section 106 standards as well as Senate Bill 18 (Tribal Consultation Guidelines) enacted on March 1, 2005, to conduct a Sacred Lands File Search and to provide a list of potentially interested Native American groups and/or individuals in the area. If Sacred Lands or Traditional Cultural Properties are present in the project area, they are subject to the same impacts as archaeological sites. Natural Investigations would contact each of the organizations or individuals provided by NAHC for information pertaining to the project area. We would maintain adequate documentation of this process, and would address any concerns from any Native American group or individual. Natural Investigations may recommend that opportunities be made for representatives of local Native American tribes or groups to participate in planned fieldwork (e.g., test excavations, surveys, or monitoring).


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