1500/1600s Mandan, Arikara or Hidatsa - Slate Celt (Axe Head) - Great Patina

Description

Nicely made slate celt or axe head made long ago by Missouri River Villagers who probably quarried the rock in the Black Hills of South Dakota.
This celt was found on private property (in Morton County, North Dakota) near an old earthen mound village adjacent to the Missouri & Heart Rivers, so this is early Mandan, Arikara, or Hidatsa. An incredible piece of Native American history.
Given the patina, use wear, and location of find, this is very old and pre-dates the metal axe trade era (i.e., 1700s). Best date estimate for this is 1600s.
I acquired this celt (along with the hide scraper and rib knife shown in the last picture -- please note these items are being sold separately) from an old collector in the Bismarck area.
If you have any questions please ask. Be sure to check my other items, as I'm selling my entire Native American art and artifacts collection.