The Promontory caves (Utah) and Franktown Cave (Colorado) contain high-fidelity records of short-term occupations by groups with material culture connections to the Subarctic/Northern Plains. This research uses Promontory and Franktown bison dung, hair, hide, and bone collagen to establish local baseline carbon isotopic variability and identify leather from a distant source. The ankle wrap of one Promontory Cave 1 moccasin had a δ¹³C value that indicates a substantial C₄ component to the animal’s diet, unlike the C₃ diets inferred from 171 other Promontory and northern Utah bison samples. We draw on a unique combination of multi-tissue isotopic analysis, carbon isoscapes, ancient DNA (species and sex identification), tissue turnover rates, archaeological contexts, and bison ecology to show that the high δ¹³C value was not likely a result of local plant consumption, bison mobility, or trade. Rather, the bison hide was likely acquired via long-distance travel to/from an area of abundant C₄ grasses far to the south or east. Expansive landscape knowledge gained through long-distance associations would have allowed Promontory caves inhabitants to make well-informed decisions about directions and routes of movement for a territorial shift, which seems to have occurred in the late thirteenth century.

We analyzed the FS-305 moccasin ankle wrap specimen at the UCSC Paleogenomics ancient DNA laboratory (PGL) to (1) obtain a taxonomic identification, and (2) determine the sex of the animal. Working in the sterile laboratory facilities at the PGL, we washed the sample in ultra-pure water to remove soil from the exterior and then extracted DNA from 0.15g of tissue following the Dabney et al. (2013) tissue extraction protocol. We prepared two shotgun sequencing libraries following the Meyer and Kircher (2010) method. We labelled the libraries using dual indices with truseq sequencing adapters and, after transferring the PCRs to the modern DNA facility, amplified them with Kappa Hifi for 25 cycles. We pooled and sequenced the libraries across several Illumina Miseq 2x75bp runs. We used Seqprep2 and prinseq (v. 0.20.4) to remove adapters and merge reads, and aligned the resulting data to the nucleotide BLAST database using MEGAN (v. 6.18.0) to identify the taxonomic origin of the tissue. In addition and to confirm the species ID, we used BWA (v. 0.7.12-r1039) to align each read to bison (Bison bison; NCBI GCA_000754665), cattle (Bos taurus; NCBI Btau_4.6.1), bighorn sheep (Ovis canadensis; NCBI CP011912.1), and two-toed sloth (Choloepus hoffmanni; NCBI5KN174222.1) genomes.

We have uploaded alignments (.bam files) of these shotgun data to bison (Bison bison; NCBI GCA_000754665), cattle (Bos taurus; NCBI Btau_4.6.1), bighorn sheep (Ovis canadensis; NCBI CP011912.1), and two-toed sloth (Choloepus hoffmanni; NCBI5KN174222.1) genomes. We have not supplied raw shotgun data because there is a chance that ancient human DNA could be examined from these Moccasin samples and we do not have permission to study this DNA.