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 multitissue 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. Instead, 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.

海角洞穴（犹他州）和弗兰克敦洞穴（科罗拉多州）包含与亚北极/北部平原有物质文化联系的群体的短期职业的高保真记录。这项研究使用 Promontory 和 Franktown 野牛粪便、毛发、皮革和骨胶原蛋白来建立本地基线碳同位素变异性并识别来自遥远来源的皮革。与 C 3不同，一种 Promontory Cave 1 软皮鞋的脚踝包裹物具有 δ 13 C 值，表明该动物的饮食中有大量的 C 4成分从其他 171 个海角和犹他州北部野牛样本推断出的饮食。我们利用多组织同位素分析、碳等位图、古代 DNA（物种和性别鉴定）、组织更新率、考古背景和野牛生态学的独特组合来表明高 δ 13 C 值不太可能是当地植物的结果消费、野牛流动性或贸易。取而代之的是，野牛皮很可能是通过长途跋涉到/从遥远的南部或东部丰富的 C 4草区域获得的。通过远距离联系获得的广泛景观知识将使海角洞穴居民能够就领土转移的方向和移动路线做出明智的决定，这似乎发生在 13 世纪后期。