The Bakken Formation is a major unconventional shale play in North America, which lacks an independent calibration for accurately correlate thermal maturity from programmed pyrolysis (via temperature of maximum pyrolysis yield, T-max) with optical methods (e.g., bitumen reflectance). In the present study, several samples from the upper and lower members of the Bakken Formation in North Dakota were analyzed by detailed organic petrography, bitumen reflectance, and Rock-Eval 6 pyrolysis. Organic petrography showed that the organic matter consists of various types of bitumen, amorphous matrix bituminite, liptodetrinite, acanthomorphic acritarch, marine alginite, granular micrinite, and inertinite macerals. Fluorescence color under UV light of macerals from the liptinite group was used to confirm the thermal maturity level. Due to the scarcity/absence of primary vitrinite, R-O measurements on solid bitumen particles were converted to equivalent vitrinite reflectance (VRO-Eq) using a published correlation equation from the coeval New Albany Shale. Overall, geochemical analysis from Rock-Eval pyrolysis reveals almost similar trends for the upper and lower members, which allowed proposing a single correlation for VRO-Eq to T-max for the Bakken Shale. Comparing the observed relationship for the Bakken Shale with the previously established models for the Devonian Duvemay Shale (Canada) and the Mississippian Barnett Shale (United States) shows discrepancies. Results confirmed the necessity of developing a specific equation for the Bakken Shale members to relate vitrinite and solid bitumen reflectance data to T-max from Rock-Eval pyrolysis. Furthermore, the outcome of this study indicated that linear trends cannot accurately represent the relationship between these two parameters, considering the kerogen kinetics and non-linear relationship between transformation ratio (TR) and T-max Therefore, a polynomial correlation, a better fit to the data, was proposed to more accurately represent the nature of this relationship.