Dynamic action in 15, 17, 18 Gaps in-- Devil's Lake Gap 3, 13 Lower Narrows 5, 13, 67 Narrows Creek 66 Upper Narrows 5, 10, 17, 19, 67 Igneous rock in 18 Structure of 15 Topography of 5, 13 Base-level 47 Base-level plains 50 Bowlder clay 97 Breccia 18 Castle Rock 71 Cleopatra's Needle 65 Cold Water Canyon 70 Conglomerate 10, 28 Basal (Potsdam) 29 Corrasion 36 Cross-bedding 30 Cycle of erosion 44, 47 Dalles of the Wisconsin 69 Origin of 53 Scenery of 69, 140 Dell Creek 53 Deltas 30, 56, 120 Deposits-- By extra-glacial waters 115-123 By ice 85, 94 By rivers 55, 56 By subglacial streams 124 Of drift classified 127 Devil's Doorway 65 Devil's Lake 132 History of 132 In glacial times 132 Location 3, 9 Origin of 132 Devil's Nose 5, 110 Divides, Shifting of 44 Dorward's Glen 10, 14, 29, 68 Drift 73 Characteristics of 96