中央华盛顿大学的地质学家卡尔·利尔奎斯特认为,这些骨骼化石曾被堆积在溪流沙砾层的顶部,后来又被一场泥流所淹没。
CWU geologist Karl Lillquist helped establish that the bones were deposited on top of creek gravel and then buried by a mudslide .