Six species of the albibarbis complex of Efferia Coquillett are reported from the Grand Canyon ecoregion on the southern Colorado Plateau in northern Arizona. The terminalia of E. albibarbis (Macquart), E. bicolor (Bellardi) E. carbonaria sp. nov., E. fisheri sp. nov., E. tapeats sp. nov., and E. zonata (Hine) are figured and compared with congeners. Efferia peralta Wilcox and E. vertebrata (Bromley) are included as comparisons and possible members of the Grand Canyon faunas. The range of E. bicolor has been extended northward from central Arizona to within 51.5 km of the south rim of the Grand Canyon and into Nye County, Nevada. Efferia fisheri is recorded along the southern edge of the plateau at Payson, AZ, 169 km south of the GCNP. Taxonomic and distribution notes are provided. Wilcox's key of this complex is revised to include all species described since his publication. Four of the six species overlap in low-elevation perennial stream riparian zones and in adjacent colluvial brecchia habitats in the Grand Canyon region. Efferia bicolor, E. fisheri, and E. zonata overlap at higher elevations.