I found this species common in one small quarter section along Jaster Road. The population of this shrub is readily visible if you zoom in on this section on Google Earth/Maps particularly on the west side of the road (last image). Neither Turner et al. (2003), USDA PLANTS, nor BONAP map A. canescens in Dallam County but it's all around the area, so this isn't a terribly surprising record.
http://bonap.net/MapGallery/County/Atriplex%20canescens.png
https://plants.sc.egov.usda.gov/home/plantProfile?symbol=ATCA2
Had a great time with some folks surveying this area in Grapevine -- great habitat here!
Population located and identity confirmed at the time by Shirley Lusk who was present.