The area between the Montezuma marshes and Oneida Lake has one of the densest concentrations of Indigenous sites in New York. Many of these are located in the northern portion of Onondaga County between the well-known locales of Jacks Reef and Brewerton. Several of these sites, excavated by William Ritchie, James Tuck, and others, have provided the basis for much of our understanding of the Indigenous presence on and uses of these riverine lowlands during the Holocene. These Seneca River sites provide a different perspective on patterns of settlement and resource use in this portion of the Lake Ontario Plain between approximately AD 1000 and 1600. They also serve as a counterpoint to the better-known Onondaga-related Iroquoian sites located in the southern portion of Onondaga County, especially in the Pompey Hills.