Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       Astra Plinius - celestial bodies
         Universe
           (Supercluster) Virgo-Hydra-Centaurus Supercluster
             (Supercluster) Virgo Supercluster
               (Cluster) Local Group
                 (Galaxy) Milky Way Galaxy veter.
                   (Spiral arm) Orion Arm
                     (Region) Local Bubble
                       Local Interstellar Cloud
                         (Planetary system) Solar System
                           (Planet-satellite system) Earth System
                             (Planet) Earth veter.
                               "spheres" (Earth)
                                 (Sphere) Biosphere (Earth) - zone of life
                                   "terrestrial and freshwater ecoregions"
                                     (Bioregion) New World
                                       (Biogeographic realm) Nearctic
                                         "terrestrial ecoregions" (Nearctic)
                                           (Terrestrial ecoregion) South Central Rockies forests (Nearctic)
                                             "United States" (South Central Rockies forests)
                                               1 "Idaho" (United States; South Central Rockies forests)
                                               2 "Montana" (United States; South Central Rockies forests)
                                               3 Greater Yellowstone Ecosystem
                                               4 "Wyoming" (United States; South Central Rockies forests)
                                               5 "South Dakota" (United States; South Central Rockies forests)