Promontory Culture in Eastern Colorado: Franktown Cave and Early Proto-Apachean Migration

Author(s): Kevin P. Gilmore; Derek Hamilton; John W. Ives

Year: 2017


Similarities between contemporaneous occupations from the Promontory Caves in Utah and Franktown Cave in eastern Colorado provide evidence of a pre-A.D. 1300 migration of proto-Apachean speakers into the Rocky Mountain west using both Intermontane and Plains margin migration routes. Bayesian modeling of Promontory Culture AMS dates from Franktown Cave suggests a 40-85 year occupation starting in the early A.D. 13th century that likely overlaps the modeled 25-55 year occupation of Promontory Cave 1 during the late 13th century. Using moccasin size as a proxy for age, the complete Franktown Cave moccasin was likely made for a 4-5 year-old child. Isotopic values (δ13C) for bison leather from Franktown Cave suggest that bison from northern and southern herds were exploited and products made from their hides were discarded at the site. These data indicate the Promontory Culture group at Franktown Cave was mixed in age, suggesting migrants (rather than scouting groups) that traveled widely or had trade connections both north and south. Increased climate variability during the MCA-LIA transition in the 13th century may have contributed to social turmoil and decreasing human population in eastern Colorado, allowing early proto-Apacheans opportunity to move through the area as bison range expanded to the south.

Cite this Record

Promontory Culture in Eastern Colorado: Franktown Cave and Early Proto-Apachean Migration. Kevin P. Gilmore, Derek Hamilton, John W. Ives. Presented at The 81st Annual Meeting of the Society for American Archaeology, Vancouver, British Columbia. 2017 ( tDAR id: 431876)


Geographic Keywords
North America - Plains

Spatial Coverage

min long: -113.95; min lat: 30.751 ; max long: -97.163; max lat: 48.865 ;

Record Identifiers

Abstract Id(s): 15234