'Department of the Interior, United States Geological Survey. TEI-840.' 'Prepared in cooperation with the U.S. Atomic Energy Commission.' 'Contours in northwest Las Vegas Valley from Malmberg, 1961.' Relief shown by contours. Shows township and range lines. Scale [ca. 1:253,440. 1 in.=aprrox. 4 miles] (W 114°00´--W 115°00´--N 37°00´/N 36°00´). Originally published in A summary of the ground-water hydrology of the area between the Las Vegas Valley and the Amargosa Desert, Nevada : with special reference to the effects of possible new withdrawals of ground water / by Isaac J. Winograd, published by the U.S. Geological Survey in 1963 as number 840 of the Trace elements investigations report.