Eight new species of Eucosma Hübner (Tortricidae) are described from western North America: E. angelana, E. blanchardi, E. candida, E. johnstoni, E. lafontainei, E. maculosa, E. mescalerana, and E. rufocostana. Eucosma conspiciendana Heinrich and Eucosma cataclystiana (Walker) are reviewed due to similarity in forewing appearance to E. rufocostana. Illustrations of the adults and genitalia are provided.