The Grand Ronde Reservation was established at the base of the mountain in the Grand Ronde Valley in 1856, and the people of an estimated twenty-nine western Oregon tribes were removed to join the Yamhills there. Spirit Mountain is in the traditional homeland of the Yamel Kalapuyans, who occupied the land at the foot of the mountain and the surrounding river valleys.
To about 2,000 feet deep, the mountain is composed of the Nestucca formation of sandstone, siltstone, and marine fossils that date to the Upper Eocene (33.9 million years ago) of the Tertiary period. It is drained by Cosper, Tindle, Rogue River (different from the Rogue River of southern Oregon), Agency, and Joe Creeks, all of which feed into the South Yamhill River.
Rising to 1,759 feet, the mountain is part of the Grand Ronde and Springer Mountain USGS quadrangles. Spirit Mountain, whose Yamel (Yamhill) Kalapuya name is dji’ntu, is a sacred site to the Confederated Tribes of Grand Ronde.
