Basal heat flow from the crystalline basement and lithospheric mantle into the sedimentary column is a required boundary condition in the petroleum systems model. The model uses two basal heat flow conditions that are described using two ASCII grids that show map variations in heat flow (mW/m2). The “BHF000_BasalHeatFlow_Calib.asc” grid describes the modern-day basal heat flow calibrated to, and derived from subsurface temperature data, including 24 high-resolution static temperature logs from the North Dakota Geological Survey and a large proprietary dataset (>1,000) of drill stem test (DST) and bottom hole temperatures (BHT) from boreholes throughout Montana and North Dakota provided by IHS Markit ® (2022). This grid is applied in the model from time steps 542 Ma to 97 Ma and again from 43 Ma to 0 Ma. The “BHF050_BasalHeatFlow_Laramide.asc” grid is transformed from the “BHF000_BasalHeatFlow_Calib.asc” grid by -10 mW/m2. The “BHF050_BasalHeatFlow_Laramide.asc” grid is applied from time steps 90 Ma to 50 Ma. The model interpolates time steps between assigned basal flow conditions. This is a child item of a larger data release titled "Data release for the 3D petroleum systems model of the Williston Basin, USA".