Abstract Middle Park, a high-altitude basin in the Southern Rocky Mountains of north central Colorado, contains abundant evidence of Paleoindian occupation. At Barger Gulch Locality B, an extensive Folsom assemblage (ca. 10,900-10,200 14C yr B.P.) occurs within a buried soil informally referred to as the Barger soil, a composite of a truncated latest Pleistocene soil and a younger soil forming during the early to middle Holocene. Erosion documented in valley fill adjacent to the excavation area between ca. 10,200 and 9700 14C yr B.P. is likely related to truncation of the latest Pleistocene soil. Relatively rapid valley filling until sometime after ca. 9350 14C yr B.P. was followed by stability and Barger soil formation until ca. 6000 14C yr B.P. Soil dates in the excavation area indicate the Barger soil was forming as late as ca. 5200 14C yr B.P. The highest of three Holocene terraces along the main axis of Barger Gulch records erosion occurring ca. 10,000-9700 14C yr B.P. followed by rapid aggradation ca. 9700-9500 14C yr B.P. Charcoal layers and lenses are common in earliest Holocene valley fills, suggesting relatively frequent and widespread burning in the Barger Gulch drainage. Aggradation rates slowed and cumulic soil formation occurred between ca. 9500 and 7500 14C yr B.P., at least partially overlapping with Barger soil formation at Locality B. Chipped stone in association with charcoal dated to ca. 8500 14C yr B.P. occurs in the cumulic soil. Morphological characteristics of upland soils in Barger Gulch and elsewhere in Middle Park suggest expansion of forest and grass cover during the early and middle Holocene in areas currently characterized by sagebrush steppe. Geoarchaeological research in Barger Gulch has thus yielded information important to understanding late Quaternary landscape evolution, characteristics of Paleoindian landscapes, and Holocene environmental change. Keywords: geoarchaeology, Southern Rocky Mountains, Paleoindian, Folsom, soil stratigraphy