The Okwanuchu occupied territory south, southwest, and southeast of Mount Shasta in California, including the present-day cities of Mount Shasta, California, McCloud, California and Dunsmuir, California; on the upper Sacramento River downstream to North Salt Creek; in the Yet Atwam Creek drainage; and on the upper McCloud River downstream to where it meets Yet Atwam Creek.
Very little is known about the location of their villages and settlements, or about their culture, other than a presumed similarity to their Shasta and Achomawi neighbors.
The archaeological sites associated with their range date back in excess of 5,000 years.
The Wintu possessed superior technology, were out-competing their Hokan-language family neighbors, and were expanding Wintu territory at the expense of the Okwanuchu and the Achomawi to the north, and the Yana to the east.
It appears likely that even if Europeans and Americans not intervened (beginning in the 1820s), the Wintu would have absorbed or otherwise eliminated the Okwanuchu over the course of the coming centuries.