We identified a 3000-year-old specimen from the Traditional Territory of the Tr’ondëk Hwëch’in in central Yukon Territory, Canada as the first known mummified remains of an ancient North American porcupine (Erethizon dorsatum), known as “Ts’ey” in the Hän language, using genetic analysis and metagenomic validation. Our analysis of the sample yielded the first-ever complete ancient mitochondrial genome for (E. dorsatum) and only the second full mitogenome for the species. Its Holocene age is considerably younger than the Pleistocene megafauna typically recovered in the Yukon permafrost, demonstrating the potential for these deposits to preserve specimens from interglacial periods. Crucially, this finding confirms the presence of porcupines in the region 3000 years ago, in line with the hypothesis that this species only dispersed into Yukon and Alaska following the establishment of boreal forests after the Last Glacial Period.