These data tables describe biogeoclimatic units for Western North America. These data were assembled as inputs to the Climate Change Informed Species Selection (CCISS) framework. The CCISS framework is built on Biogeoclimatic Ecosystem Classification (BEC). CCISS uses spatial climatic analogs (BEC subzone/variants) to make inferences about future tree species suitability, known as biogeoclimatic projections. Creating species suitability projections for the future climates of British Columbia requires finding climate analogs in Alberta and the Western US. For Alberta, we adapted the Ecological Classification of Alberta (e.g., Archibald et al. 1996), with 21 natural subregions (Natural Regions Committee 2006) as the biogeoclimatic map units and 167 ecological sites as the site series units. For Washington, Idaho, Montana, Oregon, northern California, and northwestern Wyoming, we use a draft biogeoclimatic ecosystem classification for the Western US developed by Del Meidinger and Will MacKenzie. Biogeoclimatic units are detailed in the: Western North America Biogeoclimatic Units Attribute Table. The CCISS tool predicts climate change implications to tree species environmental suitability at a site series level. We have compiled sites series information for Western North America biogeoclimatic units, detailed in; Site Series Information Table and Edatopic Space Table.