Of plain surrounding quartzite ridge 6 Of quartzite ridges 5 Transportation by streams 55 Tributary valleys 39 Turk's Head 65 Unconformity 19 Underground water 58 Unglaciated areas 79, 142, 143 Unstratified drift 99, 102, 125 Upper Narrows 5, 10, 17, 19, 67 Valley, the-- Beginning of 37 Characteristics of, at various stages 52-54 Course of 39 How a valley gets a stream 40 Limits of 43 Valley trains 116 Waterfalls 48 Weathering 36 Webster's Prarie 119 Wisconsin Lake 129 Wisconsin River 139 Witch's Gulch 70