Page "Algonquian languages" Paragraph 50

This historical reconstruction accords best with the observed levels of divergence within the family, whereby the most divergent languages are found furthest west ( since they constitute the earliest branchings during eastern migration ), and the shallowest subgroupings are found furthest to the east ( Eastern Algonquian, and arguably Core Central ).

Goddard also points out that there is clear evidence for pre-historical contact between Eastern Algonquian and Cree-Montagnais, as well as between Cheyenne and Arapaho-Gros Ventre.

There has long been especially extensive back-and-forth influence between Cree and Ojibwe.