Bulletin - United States Geological Survey (1915) - neues Buch

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: approximately 7,900 feet above sea level in the valley bottoms and lowest depressions to 8,100 feet at the town of Walden, which is probably very near the average altitude of the greater part of the park floor. Many local areas in the north-central and south-central parts of the park are extremely flat, but few such areas are more than 20 to 30 square miles in extent and most of them are surrounded by somewhat rolling areas that have long even slopes, in which abrupt changes in altitude occur only where the benches or uplands drop off suddenly into the stream valleys. MINOR FEATURES. The prevailing flatness of the park floor is locally broken by ridges, hills, and small mesas, which appear prominent when viewed from the lower level areas, but which become insignificant when viewed from the summits of the Park or Medicine Bow ranges. The most prominent of these minor features is the long hogback-like ridge which rises 1,000 to 1,500 feet above the park floor and extends from the northwest corner of the park south-southeastward about halfway to the southern boundary, terminating abruptly at the south end of Delanos Butte. This ridge runs approximately parallel to the east base of the Park Range and is separated from it by the valley of North Fork of Platte River. The valley is about 3 miles wide west of Delanos Butte and Sheep Mountain but is much narrower farther north, where it is partly filled by the moraines from Zirkel Mountain. The ridge is broken by two gaps. One of them lies east of the Boet- cher ranch, separating Sheep Mountain from the main ridge on the north; the other is a gap cut by North Platte River between Sheep Mountain and Delanos Butte on the south. The ridge is formed by immense wedges of granite, most of them sharp along the crest. In many places along th...