Northwest Plains Projectile point Chronology

Time line
 Historic/Protohistoric- 500 to 150 BP
 Late Prehistoric- 650to 1,900 BP
 Late Archaic- 1,900 to 4,100 BP
 Early Archaic- 4,100 to 8,100 (roughly)
 Paleo-Indian - 8,100 to 12,000

Projectile point Chronology
• Protohistoric/historic- from a few fifties of years up to present, a few Tri-notched and Plains Side Notched.
• Late prehistoric 250 BP to 1,900 BP- Triangular, Prairie Side Notched, Avonlea, Tri-notched and Plains Side Notched.
• Archaic/ Middle Prehistoric 1,900BP to 7,500- Bitterroot, Pelican Lake, Oxbow, Hanna, Duncan, McKean, and Besant (also found a little in Late Prehistoric).
• Paleo-Indian/ Early Prehistoric- Hell Gap, Scotts Bluff, Eden, Agate Basin, and Clovis (attached to Folsom and Goshen discussed below).
The Folsom complex follows the Clovis period they both overlap with Goshen (dating indefinite). Folsom projectile points, radiocarbon dating states they were in the area from roughly 10,900 to 10,200 BP.
Midland level following Folsom dated between 10,700 and 10,400 BP. Projectile point similar to Folsom except for lack of fluting.
The Hell Gap Cultural complex had radiocarbon dating from 10,300 to 9,500 BP.
Early plains Archaic started (best found points for radiocarbon dating in Mummy cave) 8,500 BP ended (Mummy cave) 5,250 BP.

Picture website

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