Seventeen 115Kv transmission towers supplying utility services to residents and surrounding businesses in Jackson Hole, Wyoming, were damaged by a severe windstorm in February 2017. The storm resulted in the approval of a disaster declaration for the state. Teton County occupies mountainous terrain in the northwest corner of Wyoming, south of Yellowstone and Grand Teton National Parks.
The utility company services a ski resort, an airport, residential and rental homes, and local businesses. Instead of repairing damage from the disaster, the local energy company applied for and was awarded funding through a grant program to bury electrical cables and help prevent future outages from happening following inclement storms or weather. The approved work occurred along a 12,000-foot-long corridor at an elevation of 6,350 feet.
Challenges
In June of 2017, Environmental Planning and Historic Preservation (EHP) advisors began working with the Wyoming State Historic Preservation Office (SHPO) to provide sound guidance and ensure all environmental regulations and executive orders were met prior to construction.
The project area had a variety of cultural resources surveys over two decades, with no historic properties noted – despite its archaeologically sensitive nature. SHPO determined a low likelihood of historic properties being impacted, but stipulated construction monitoring to be sure. In support of our state partners, EHP advisors prepared an archaeological monitoring plan and guided archaeologists for more than two months. EHP advisors made sure SHPO’s criteria of sites, and excavation, analysis, and reporting standards were followed. Monitoring protocol mandated “salvage” excavation of features, provided EHP and SHPO were consulted. EHP and SHPO were contacted as a series of aboriginal features were found.
Outcome
Almost 300 stone artifacts (local obsidian) – including 10 bifacial and ground stone tools were recovered. This site had multiple, short-term occupations between 1410 and 1100 years before present BP), but with no temporally diagnostic artifacts. Macrofloral analysis of features showed geophytes (bulb, tuber, or a thick rhizome), cactus pads, and grass seeds were processed. The site is on the western side of a hill, minimally measures 572 m² in area, and is buried in loses on glacial moraine. The assemblage was limited to burned rock, 11 flakes (quartzite and obsidian), and two modified cobbles. Plant processing activities were not identified, and no temporally diagnostic artifacts were recovered.
The archaeological sites were National Register eligible for potential information on chronology, hunter-gatherer settlement/subsistence (seasonal transhumance), lithic procurement, and mountain adaptations by pre-contact Native Americans within the greater Yellowstone Ecosystem. The occupations also have significance within glacial moraine loess and alluvium deposits in a transition zone between meadow-sagebrush community and high elevation zones of the Teton Mountains – areas not frequently reported in the regional archaeological literature.
SHPO accepted the findings and agreed monitoring met its objectives. Minimal damage occurred to the sites and the salvage excavations were effective. All parties concluded the sites contain buried cultural materials.
EHP continued consultation with SHPO and the Advisory Council on Historic Preservation (ACHP) through June of 2018. SHPO and ACHP concurred with the findings and recommendations to develop a Memorandum of Agreement (MOA) to address “after-the-fact” data recovery efforts. The memorandum was finalized between FEMA, SHPO, ACHP, the utility company, the Wyoming Office of Homeland Security, various tribes, and other interested parties.
EHP recommended specialized analyses on the remains for mitigation. Treatment of adverse effects (based on a Data Recovery Plan drafted by EHP) included:
- Developing a geomorphic and regional cultural context (including Late Holocene hunter-gatherer seasonal transhumance in the context of high-altitude subsistence/settlement).
- Macrobotanical analysis of the feature fill, residue analysis of stone tools, and geochemical analysis/optical stimulated luminescence dating (OSL) of obsidian artifacts.
- Public involvement (including tribes and local historic and archaeological groups).
- A non-technical publication and a publication in a regional archaeological journal.
Consultation occurred with a variety of tribal representatives and local historical organizations as the sites were discovered and while the SHPO and ACHP negotiations were occurring. The final report was completed in July of 2019 by EHP advisors and included appendices on geoarchaeological contexts and a site burial model for the region, macrofloral and starch grain analysis, Energy Dispersive X-ray Fluorescence analysis and sourcing of 30 obsidian specimens, and radiocarbon dating. Data recovered a better understanding of precontact humans in Jackson Hole and how they relate to the larger Great Yellowstone Ecosystem.