The supplemental data presented here contains three raster datasets representing the evapotranspiration (ET) units for northern, southern, and western regions of Harney Basin (raster datasets in .tif format) and one vector dataset of ET-unit observations used to delineate ET units (vector dataset in .shp format). Eleven ET units were identified from ET-unit observations of land cover and include bare soil or playa (1), marsh (2), dry meadow (3), wet meadow (4), open water (5), riparian (6), mixed shrubland (7), phreatophyte shrubland (8), xerophyte shrubland (9), sagebrush shrubland (10), and xerophyte grassland (11). Irrigated areas are excluded from ET units. Unpublished land-cover datasets collected by the U.S. Bureau of Land Management (BLM) and U.S. Fish and Wildlife Service (USFWS) were used, in part, to generate ET-unit observations and are provided (vector datasets in .shp and .csv format) in the sub-child item, Harney Basin Land-Cover Observations.