This report describes the geology of an area in northwestern Alberta contained largely within N.T.S. Sheet 83L (Wapiti) and the northeast portion of N.T.S Sheet 83E (Mount Robson). The region is traversed by three alternative routes for a proposed multipurpose highway connecting the City of Grande Prairie on the northern margin of the map area and the town of Grande Cache in the Foothills to the southwest. The report is written with particular reference to the geological factors associated with the siting of this highway, as requested by the Department of Highways and Transport.
Most of the data on the bedrock geology of the area, except the Foothills in the southwest, was obtained from helicopter surveys conducted by Research Council Geology Division personnel in 1969 and 1970. This material is supplemented by information in reports by Allan and Carr (1946), Greiner (1955), and Irish (1965), and by examination of air photos.
The surficial deposits of the area have not been mapped, although some data are available in a reconnaissance soils survey report by Lindsay et al. (1963). Air photo examination and observations of surficial deposits made during bedrock geology surveys also have proved helpful.