This data set was used to trace changes in forest fire frequency, plant ecology, and climate in the Western US and Western Interior Seaway (WIS) through Oceanic Anoxic Event 2 (OAE2; ~94 Ma). Samples were present in the SH#1 core, which was recovered in the summer of 2014 near Big Water, Utah (37.158466°N, 111.531947°W). Biomarker data was produced using gas chromatography-mass spectrometry between February 2016 and April 2019, and is presented either in concentrations normalized to total organic carbon (ug/g TOC), or as a ratio of biomarker/s to other biomarker/s. Combustion-derived polycyclic aromatic hydrocarbons (PAHs) were used to trace forest fires, land plant-derived long chain n-alkanes (LCAs) were used to trace changes in the input of terrestrial organic matter to the WIS, and the average chain length (ACL) of LCAs helped to deduce changes in plant community and precipitation in the Western US. The R markdown contains the processing of raw biomarker data and calculations for ratios, as well as the code for carbon mass balance equations that assess the significance of fires during OAE2.