\j-n_rLL-T. 



NOTE 



Seven volumes, accompanied by one Topographical and one Geological 

 Atlas, embrace reports upon Geographical Surveys of the territory of the 

 United States West of the One hundredth Meridian of longitude from 

 Greenwich, as follows: 



Volume I. — Geographical Report. 

 Volume II. — Astronomy and Barometric Hypsometry. 



Volume III. — Geology and Mineralogy. 



Volume IV. — Paleontology. 

 Volume V. — Zoology. 



- Volume VI. — Botany. 

 Volume VII. — Archaeology. 



The Topographical Atlas edition, consisting of Title-Page, Legend, and 

 Conventional Sign Sheets, Index, Progress and Basin Maps, and Sheets 

 Nos.49, 50, 58, 50, 66, 67, 75, 76, 83, 53 (C), 61 (B), 61 (C), 61 (d), 61 

 (D), 62 (A), 62 (C), 65 (D), 69 (B), 69 (D), 70 (A), 70 (C), and 77 (13) have 

 been issued at date of sending forward the MS. of this volume. Other 

 sheets, of which there are twenty-seven in various stages of completion, 

 will follow as rapidly as they can be prepared, engraved, and printed. 



Sheets 53 (C), 61 (B), 61 (C), 61 (D), 62 (A), 62 (C), 65 (D), 69 (B), 

 69 (D), 70 (A), 70 (C), and 77 (B) are projected upon a scale of 1 inch to 

 4 miles, while the scale of 1 inch to 2 miles has been used for sheet 61 

 (Cj), the latter embracing a part of the San Juan mining region ot 

 Southwestern Colorado. The scale of 1 inch to 1 mile has been selected 

 for the six-sheet map of the lake region of the Sierra Nevada encircling 

 Lake Tahoe ; and the contour map of the Washoe Mining District, in which 



