That is indeed bazaar. I'm from Montana, and an anthropologist, we have the facilities and people to investigate this who are probably more knowledgable in Montana history than people at BYU. My guess is that some mormon found it and sent it to BYU because Montana State University and the University of Montana don't teach the "correct" history of the earth, or they wanted to give BYU support for the BOM.
Either that or somebody potted them out in Utah or the 4 corners and wanted to send them home.
I remember going along with my physical anthro professor to look at human bones that had been found in grandpa's attic after he died (this was in Washington State). Turned out to be an Anasazi basket burial. It is amazing, and disgusting, what some people will collect.