I see sentences like "[Wampanoag] oral tradition points towards a relative stability in governance and culture before contact and afterwards" on this sub, mentions of Iroquois Keepers whose knowledge is vital for understanding their history but never sourced, and articles proclaiming memories of natural events X thousand years ago. This seems like an incredibly important and understudied source for Precolumbian history.
I'm not an expert in Indigenous Peoples of anywhere, but here are some resources. Some of these are searchable digital archives and others might require a login or to have direct contact with an agency (University etc). Different organizations focus on different groups it seems and it isn't guaranteed any source will contain info on certain tribes.
https://oral.history.ufl.edu/projects/nahp/
https://guides.lib.berkeley.edu/BancroftNativeAmericanCollections/OralHistories
https://digitalcommons.winthrop.edu/manuscriptcollection_findingaids/458/
https://digital.libraries.ou.edu/whc/duke/
https://www.atalm.org/node/437
This is not a comprehensive list.