T Tapirs [16] Tertiary Period [42], [43], [45], [46], [48] Teton River [33] Texas [7] Theodore Roosevelt National Memorial Park [35], [40] Till [34] Titanotheres [16] Tongue River [39] Trails [2] Trees [1], [2], [7] Triassic Period [21] Triceratops [16] Trinidad, Colo. [25]

U Uplift [11], [16], [19], [32], [37]

V Valley development [39] Vaughn, N. Mex. [45] Vegetation [1], [2], [7], [10], [16] Vermejo Formation [16] Volcanoes [16], [20], [40]

W Walsenburg, Colo. [24] Warping [11] Well-drilling [11] West Nueces River [46] White River [29], [39], [40] White River Group [16], [40], [44] Williston basin [11], [16], [33] Wind Cave [21] Wind deposition [44] Wyoming [20], [39]

Y Yellowstone River [33], [38]

Transcriber’s Notes