Taburan fosil Rhizocyon

  • Tapak Foree, Formasi John Day, Kaunti Wheeler, Oregon ~30.8—20.6 Ma.
  • Lapangan Terbang Longview Ranch, Formasi John Day, Kaunti Wheeler, Oregon ~30.8—20.6 Ma.
  • North Blue Basin Site, Formasi John Day, Kaunti Grant, Oregon ~33.3—30.8 Ma.
  • Kimberly Member, Formasi John Day, Kaunti Grant, Oregon ~30.8—20.6 Ma.
  • Roundup Flat (juga dikenali sebagaiSouth Haystack), Kaunti Grant, Oregon ~30.8—20.6 Ma.