Collection: Directories and Documents > Pamphlets

About This Item:

Title: The Great Watershed of California (PH 20-7)(1978) Collection Type: Directories and Documents Collection Name: Pamphlets Catalog #: PH 20-7 Author: Olaf P. Jenkins Published: 1978 # of Pages: 57 Download PDF: User Login Required Download OCR Text: User Login Required

Metadata By: Shelby Figueroa Printed or handwritten: All printed text Date Scanned: 2024-12-19 11:06:45 Scanned By: Shelby Figueroa Scanning Equipment: CZUR Book Scanner OCR Software Version #: tesseract 5.4.1 Item Sourced From: JPGs First Created: 2025-03-17 05:48:59 Last Updated: 2025-03-17 05:48:59

Original Held At: Searls Historical Library Location: 161 Nevada City Hwy, Nevada City, CA 95959

Page: of 57  

PREFACE One hundred years ago when extensive government surveys were being carried on in the Far West, the Great Basin began to attract the attention of geologists because of the widespread Pleistocene lakes which had become trapped in this interior closed basin. The interest of scientists in the phenomenal features of this particular enormous seemingly collapsed area in the midst of the high Rocky Mountain region has since never waned. Early reports outlined the Great Basin, without the benefit of accurate detailed topographic maps, which were then scarce. It was quite obvious that California had a large share in the Great Basin and that the barrier wall of the abrupt eastern side of the Sierra Nevada was more than a match to its counterpart of the Wasatch Mountains whose own high western wall stands guard over the Great Salt Lake. Waldemar Lindgren (sent out to California in 1896 by the newly organized United States Geological Survey with a group of some of the foremost geologists of the nation) completed mapping the Gold Belt of the Sierra Nevada and prepared a summary Professional Paper (173) on the Tertiary gold-bearing gravels of the Sierra. This study took him right up to the very top of the crest where the drainage boundary between the Great Basin and Pacific Ocean traverses the eastern mountains of California. In his intense interest in the geological history of how it got there and where it came from, he showed on his geologic maps of the northern Sierra, two critical lines: one is the “present divide between the Pacific Ocean and the Great Basin”; the other, the “preTertiary divide” which he also called the “Cretaceous crest line of range and the Great Basin.” Maps have always fascinated me. Shaded relief maps are beautiful to look at — they are geographic works of art. Contour maps show relief; though not so artistic, they are more accurate, because they present measured heights and distances. Other features, like the intricate lines, colors, patterns, names, and symbols which go with geologic maps can be printed right over the topographic contour maps, which also show streams, culture and more names. The one feature which none of these fine maps shows is the drainage divide lines. These are left to the hydrographers to draw on special maps, not so cluttered with information considered irrelevant. Their hydrographic maps, however, show all the water basins, not just the one that is closed — the Great Basin. That part of the Great Basin which is in California is bounded by a line running for 1000 miles from the Oregon border on the north to the Nevada border in the Mojave Desert. It runs along the unbroken crest of the high eastern mountains of the State, outlining what I call the Great Watershed of California. Part of the water falling upon the crest flows into the interior closed Great Basin and the other part joins the long western rivers whose waters finally reach the Pacific Ocean. In following this crest on topographic maps, it is found to run right over rugged peaks and through areas of critical interest, always with contrasting views on either side, without concern with the geology — its only requirement being to enclose the Basin with an unbroken border. After completing the log of the Great Watershed’s Divide, one question keeps plaguing me: Why does the divide persist in maintaining an unbroken course and — if broken — what will happen to it? Perhaps thereis the answer to its peculiar peregrinations through such places as the Mojave Desert! vii.