The Relict Dace is a small cyprinid and the only species in its genus, Relictus. It is naturally distributed in four drainage basins of central Nevada - Butte Valley, Ruby Valley, Steptoe Valley, and Goshute Valley. The species has experienced periods of isolation and connection within these four basins since the late Pliocene, with the last 100years characterized by anthropogenic disturbance. To better inform conservation actions, we investigated range-wide and intra-basin genetic structure and diversity and conducted Fst outlier tests using RAD-sequencing. We found high levels of genetic structure and four main lineages on a broad scale corresponding primarily to geography, and on a very fine scale (