A biodiversity monitoring program in south-central British Columbia, Canada, at sites on traditional nłeʔképmx territory near the Highland Valley Copper mine, collected many specimens of an unknown moth. DNA barcode analysis revealed its affinity but deep divergence (14.3%) from Tridentaforma fuscoleuca (Braun, 1923), the only species in the family Tridentaformidae. The new species was assigned to the BIN (Barcode Index Number) BOLD:AFK8960. Morphological study confirmed its placement in this family but revealed marked genitalic differences from T. fuscoleuca. Given its genetic and morphological divergence, we describe Tridentaforma browncopper Monckton & Levesque-Beaudin, sp. nov. The scientific name is a translation of the name, skʷúnkʷl̓itkax̣n̓I, chosen by nłeʔképmx Elders and Knowledge Keepers, which means "brown copper moth". Its discovery and naming reflect an effective collaboration among biodiversity scientists, industry representatives, and Indigenous communities. It also demonstrates how DNA barcoding can facilitate species descriptions without requiring taxonomists with specialist expertise in the group under investigation.