Chapter D

decomposition: 30
Devil’s Slide: 19, 40, 44
Devil’s Tombstone: 40
differential erosion: 31, 41
disintegration: 30
dugout, Col. Charles Goodnight’s: 39, 40

E
earth history: 10-12
Eastern Caprock Escarpment: 8
erosion, differential: 31, 41

F
flash floods: 29
fluorescence: 26
fluvial sediments: 24
Fortress Cliff: 1, 40, 42
fossils: 10
frost wedging: 30

G
geodes: 22
geologic column: 12
geologic time scale: 11, 12
geomorphologist: 29
Goodnight, Colonel Charles: 1, 39, 40
gypsum: 17

H
Harper, Mrs. Ples: 35
hematite: 22
Hester, W. A.: 1
High Plains: 8
hiking: 43
history of park: 3-8
“hoodoos”: 23, 31
Horn, Ron: 35
horseback riding: 43
horses: 27
hydration: 18, 31
hydraulic action: 30