Source rocks that are organic-rich have varying mineralogical composition and complex rock fabric. In this study, we aim to characterize the immature and mature Bakken shale's microstructural and elastic properties using, respectively, advanced laboratory analysis, well log data, and rock physics modeling. We perform geochemical and source rock analysis to estimate the total organic carbon (TOC) and organic matter type, followed by an X-ray diffraction analysis (XRD) to obtain the mineral composition with the corresponding volume fractions. Then, we conduct a pore-scale study with NMR T2 and SEM imaging. Finally, we estimate the elastic properties using well log data and rock physics modeling. The results obtained from this study contribute to a better understanding of the source rock microstructural and elastic properties whether in the context of petroleum geology or engineering. Using our approach presented in this study, conclusions can be drawn that there is a need to investigate how the organic content and maturity impact the geophysical properties in source rocks.