ABSTRACT The Sidney Geosol in Ohio and Indiana is believed to have developed between marine isotope stage (MIS) 5 and MIS 2. Development stopped when the Laurentide ice sheet extended south of the Great Lakes during MIS 2. Prior reported data and new chronological information are employed here to show that pedogenesis of the Sydney Geosol started prior to 50 cal ka and ended time-transgressively through burial by sediment of the Laurentide ice sheet. Near Sidney, Ohio, the termination age is ca. 25.9 cal ka, whereas at Snyder, Indiana, near the limit of the ice-sheet expansion, the age is ca. 21.9 cal ka. However, at Oxford, Ohio, an interstadial organic accumulation between till units may imply that the upper portion of the Sidney Geosol formed under different conditions than the remainder. At a third site, Huffman Park, Ohio, glacially transported tree remains represent a landscape older than 50 cal ka, which is currently difficult to correlate with any specific paleosol, but which suggests that further insights about conditions prior to ca. 25.9 cal ka may be preserved in the record.