Asarum caudatum is among the many coastal disjunct species exclusively inhabiting temperate rainforest habitats in the Pacific Northwest of North America. The distribution of rainforest species inhabiting coastal regions west of the Cascades and Coast Ranges with disjunct populations in Northern Idaho, Montana, and Southeast British Columbia has long interested biogeographers. Phylogeographic work on other coastal disjunct species has concentrated thus far on overstory trees (Thuja plicata, Tsuga heterophylla, Alnus rubra) along with amphibians and mollusks. Results from the overstory trees reveal a complex phylogeographic history with species surviving glaciation in both the Southern Cascades and unglaciated regions in Northern Idaho, with secondary gene flow post glaciation. Our null expectation for Asarum caudatum, given that it is ant pollinated and dispersed, along with other life history traits, was that it too had populations surviving in the Cascades and Rocky Mountains during glaciation, but with no secondary gene flow. Preliminary results using a ddRAD approach, however, indicate that this species recently dispersed from Southwestern Oregon north and across the Okanogan Mountains post-glaciation, proceeding to separate into northern and southern interior clades. This unexpected result gives us a clearer understanding of interior rainforest history and will inform future investigations on other understory coastal disjunct taxa.