The simplified geological map of Alberta was derived from three geological compilation maps of the province - supported as needed by field observations, analytical work and/or three-dimensional models of subsurface stratigraphy - produced by the Alberta Geological Survey (AGS): the bedrock geology of the Alberta Plains was simplified from the “Bedrock Geology Map of Alberta” (Map 600/2013, scale 1:1 000 000), the last provincial-scale geological map compilation that included existing geological maps and original geological mapping by Alberta Geological Survey (AGS) staff; the main geological features of the Alberta portion of the Canadian Shield and Athabasca Basin were selected from the compilation map “Precambrian Geology of Northeastern Alberta” (Map 537/2010, scale 1:250 000), based on previous geological maps published by the AGS and GSC; the geology of the Alberta Rockies was simplified from the compilation map “Geology of the Alberta Rocky Mountains and Foothills” (Map 560/2013, scale 1:500 000). In order to properly display the main tectonic features in the province, stratigraphic and lithological details had to be removed. Therefore, independent plutons on the Alberta shield and the internal stratigraphy of the Athabasca Group in the Athabasca Basin were not represented. Over one hundred stratigraphic units of the Western Canada Sedimentary Basin ware grouped into Mesoproterozoic (Belt-Purcell Group), Neoproterozoic (Miette Group), Paleozoic (carbonate dominated sequences) and Mesozoic to Cenozoic (mostly clastic sequences).