The dataset includes subsurface stratigraphic picks for the base of the Belly River Group/Wapiti Formation in the Alberta Plains (Townships 1 to 94, Ranges 1W4 to 14W6) made from wireline geophysical well logs. In general, the pick was made at the base of the lowest sandstone bed (overlying the Pakowki or Lea Park Formation) that was overlain by coal. If coal is absent, the pick was made at the base of the first sandstone. We screened the well data to detect errors resulting from deviated wells, as well as incorrect ground and kelly bushing elevation data. We used statistical methods to identify local and regional statistical outliers, which were examined individually.