The North American Western Interior Seaway (WIS) was a shallow epeiric seaway that extended across various parts of the continent from the Jurassic into the Paleocene during greenhouse climates. Sedimentary deposits of this seaway are an economically important source of coal and hydrocarbon reserves and are targets for geothermal and carbon capture. Therefore, accurate paleogeographic reconstructions of the seaway are critical for better constraint and prediction of the extent of productive lithofacies and paleoenvironments. Here, we present the result of an extensive literature review used to reconstruct the paleogeography of the southern half of the WIS using a multidisciplinary approach that provided new insights into the evolution of paleoshorelines and depositional environments at key intervals. We distilled sedimentology, stratigraphy, paleontology, ichnology, and geochemistry and recognized previously undocumented local and regional changes in relative sea level that had major impacts on shoreline position. Our initial investigation determined that previous paleogeographic maps may be biased by the limits of data availability. The lithostratigraphy used in the WIS is often applied to strata of different depositional environments and timeframes, highlighting a need to rely on well-established chronostratigraphic frameworks. Ichnological analyses, often overlooked in paleogeographic studies, should be used more to help define paleoshorelines and depositional environments subjected to high-frequency transgression/regression cycles. We argue that a more interdisciplinary, integrated approach should be used for future paleogeographic reconstructions to better predict facies distributions, understand past environments, and more rigorously reconstruct sea-level change.