This dataset is part of the three-dimensional (3-D) hydrostratigraphic model of the Sylvan Lake sub-basin in the Edmonton-Calgary Corridor, central Alberta. It represents the structure top of hydrostratigraphic unit (HSU) C1, which contains fine-grained materials underlying coarse-grained sediments of HSU S2 in the Neogene-Quaternary succession of the Sylvan Lake sub-basin. This dataset supplements Alberta Geological Survey (AGS) Open File Report 2014-10, which includes a full description of steps taken to produce the structure grid.