A comprehensive geochemical and stratigraphic study of Cretaceous coal-bearing strata in Utah and western Colorado was performed to evaluate geologic trends in REE-enrichment, as well as elucidate enrichment mechanisms. Preliminary portable X-ray fluorescence (pXRF) analyses (n = 5659) was combined with Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) analyses (n = 135) on particularly REE-enriched samples. Sampling and analyses from active and historic mines as well as nearby cores and outcrops were performed with an emphasis on sedimentary, stratigraphic, geographic, and mining context.