O Oglala Sioux Indians 7, 11. _See also_ _Red Cloud_ _Oligobunis_ 32 Oligocene epoch 25, 31, _46_, 49, 50, 52, 53, 70, 88; animals of 61, 63 Opossum _54-55_, 60 Ordovician period _46_ _Oreodon_ 25, _54-55_, 60, 63 Osborn, Henry F. 14, 38 Owl, great horned _83_ _Oxydactylus_ _20-21_, 22, 28, _56-57_, 60
P _Palaeocastor_ 14, _20-21_, 22, _33_, 64, _68-69_, 70-71, 77, 86 _Palaeolagus_ 34 Paleocene epoch _46_, 53 Paleozoic era _46_, 47-48 _Parahippus_ _20-21_, 22, _27_, _56-57_, 60, 62, 67 Permian period _46_ Peterson, O. A. 14, 38, 39 Petrified Forest National Park, Arizona _89_ Pigs 30-31 Pine Ridge, South Dakota 52 Pleistocene epoch 28-29, _46_, _64_, 67 Pliocene epoch 24-25, 27, _46_, 52, 63 _Portheus_ 48 Precambrian era _46_ _Promerycochoerus_ _20-21_, 22, 25, 87 Pronghorn (artiodactyls) 63, _84_. _See also_ _Syndyoceras_ _Protoceras_ 31 _Protohippus_ 62, 63 _Pseudaelurus_ 32, _58-59_, 60
R Red Cloud 9, 11 Rhinoceros 24-25, 50, 51, 63 Rocky Mountain National Park, Colorado 92 Rocky Mountain Revolution 51, 52 Runningwater Formation 51 Rodents 32-34
S Sandpiper, upland _14_ Scotts Bluff National Monument, Nebraska 49, _91_ Sheep Creek Formation 52 Silurian period _46_ Smiley Canyon, Nebraska 50 Snake, hognose _84_ _Stenomylus_ 14, _20-21_, 22, _29_, 37, _39_, 50, _64-65_, 86, 87; _hitchcocki_, 51 Sundance Formation 48 _Syndyoceras_ _20-21_, 22, _31_ _Synthetoceras_ 31-32
T Teeth, high-crowned 62-63 _Temnocyon_ 32 Tertiary period _46_, 53 Theodore Roosevelt National Park, North Dakota 92 Thompson, Albert 14, 38 Toadstool Park, Nebraska 49 Tortoise 33-34 Trailside Museum, Nebraska 86 Triassic period _46_
U Uniformitarianism 42, 43, 45 University Hill 7, _12-13_, 35; digging at, 14; formation of 37; tourist facilities at, 77 University of Nebraska State Museum 86
V Visitor information 77-80, 86-92 Von Linne, Karl _43_
W Wallace, Alfred _45_ White River 52; Badlands 31; Beds 49 Wildflowers 7, 10 Wind Cave National Park, South Dakota 91 Wren, house _82_; long-billed marsh _82_
The National Park Service expresses its appreciation to all those persons who made the preparation and production of this handbook possible. The Service also gratefully acknowledges the financial support given this handbook project by the Oregon Trail Museum Association, a nonprofit group that assists interpretive efforts at Agate Fossil Beds National Monument.