“Maybe the piles are related to that (tribal history). Maybe they aren’t,”
If they didn’t keep track of it, it couldn’t be that important... ;)
In Minneapolis, a highway project(Hiawatha Avenue) was stopped because local Native Americans claimed that stately old trees were once the above-ground burial places of Warriors. It was found they dated from the 1860's, far too young to have been used for that purpose.
In this case, the truth will out.
A simple solution would be that the Tribe(if some one is speaking for the tribe) or the individual and his estate(if some one speaks as an individual) should have to escrow an amount that would cover damages from delays. That might spare the taxpayer from Manufactured Memory Syndrome, if, heaven forbid, that's what this is.