Investigations were conducted along the middle South Platte River to better define the geomorphic contexts of Palaeo-Indian sites and to reconstruct the alluvial and eolian geochronology. Palaeo-Indian sites are associated with the Kersey terrace (the downstream equivalent of the Broadway terrace). The Kersey alluvium was deposited during Clovis occupation and the surface stabilized by 10,000 BP. Post-Clovis sites postdate aggradation and stream downcutting may have started as early as 10,500 BP. Subsequent floodplain development and downcutting formed the Kuner terrace (the possible downstream equivalent of the Piney Creek terrace) no later than 3000 BP and the Hardin terrace probably within the last 1000 years. Soils on the Kersey terrace are Ustochrepts (gravelly alluvium) or Haplustalfs (sandy and clayey alluvium). Soils on the Kuner terrace are cumulic Ustorthents and Ustochrepts. Soils on the Hardin terrace are Ustorthents with no obvious horizonation. Eolian sands began accumulating in the region by 10,000 BP, but most are probably late Holocene deposits and are indicative of drier post-Pleistocene climate. Correlations with deposits in low order tributaries and other drainages can be difficult to make using soils because soil development varies as a function of parent material texture and because aggradation and degradation may be out-of-phase.