ILLUSTRATIONS. Page. PLATE I. Map of United States, showing location of geologic field parties in II. Geologic map and section of the region around Telluride, Colo., III. Map of Alaska, showing progress of geologic and topographic recon- IV. Map of United States, showing locations of topographic field parties V. Map of United States, showing areas covered by topographic surveys. VII. A, Typical bridge gaging station-Mississippi River at Anoka, Minn.; FIG. 1. Ideal view and corresponding contour map 58 3. Map showing locations of river stations in eastern half of United States in 1903-4 ..... 2. Map showing locations of river stations and principal irrigation projects in western half of United States in 1903-4...... 80 81 4. Map showing progress of work on underground waters in western half of United States in 1903-4. 86 5 5. Map showing progress of work on underground waters in eastern half of United States in 1903–4.. 87 LETTER OF TRANSMITTAL. DEPARTMENT OF THE INTERIOR, UNITED STATES GEOLOGICAL SURVEY, Washington, D. C., February 18, 1904. SIR: There is presented herewith, for publication as a bulletin, an account of the origin, development, and present organization of the United States Geological Survey, with short summaries of its various operations during the first quarter-century of its existence. This bulletin has been prepared in accordance with your instructions, and it is believed that it will be read with interest generally, both in this country and abroad, as a brief record of the rise, growth, administration, and work of an important branch of the public service. Very respectfully, Hon. CHARLES D. WALCOTT, H. C. RIZER, Chief Clerk. Director of United States Geological Survey. 7 THE UNITED STATES GEOLOGICAL SURVEY: ITS ORIGIN, DEVELOPMENT, ORGANIZATION, AND OPERATIONS. INTRODUCTION. ORIGIN AND DEVELOPMENT OF THE SURVEY. The United States Geological Survey, in the Department of the Interior, was created by act of Congress approved March 3, 1879, so that March 3, 1904, marks the completion of the twenty-fifth year of its existence. The quarter-century anniversary happens to fall near the date set for the opening of the Louisiana Purchase Exposition at St. Louis, at which the Survey will make an exhibit. It is hoped that many of the people of this country will be interested in that exhibit, and, in connection therewith, it has been thought desirable to place before the public, by means of a small bulletin, an account of the organization and work of the Survey and the results it has achieved. Prior to the date of the act above mentioned five Federal surveys had been engaged in mapping portions of the territory of the United States. The oldest of these, the Coast and Geodetic Survey, had restricted its mapping to the coast line, but had extended certain geodetic and scientific investigations over various portions of the country. The other four organizations had made topographic, geologic, and other scientific and economic surveys in the Territories west of the one hundredth meridian. The Geological Exploration of the Fortieth Parallel was engaged from 1867 to 1872, under the direction of Mr. Clarence King, in surveying a zone, 105 miles wide, extending from the meridian of 104° to that of 120° west of Greenwich, and comprising an area of 86,390 square miles. The Geological and Geographical Survey of the Territories, under Dr. F. V. Hayden, between 1873 and 1878, surveyed areas in Colorado, New Mexico, Utah, Wyoming, and Idaho, comprising about 100,000 square miles. The Geographical Survey West of the One Hundredth Meridian, under Capt. George M. Wheeler, U. S. Army, was engaged in extending surveys in various portions of the country west of the meridian named in its title. It surveyed an area of about 359,000 square miles. The work of the Geographical and Geological Survey of the Rocky Mountain Region, under |