TOPOGKAPHIO FEATUEES OF THE DESERT BASINS. 3 



and where these were available other data have seldom been sought. 

 For areas as yet unsurveyed by the Geological Survey, use has been 

 made of the maps of the Wheeler and King surveys, of the maps 

 and notes of the General Land Office surveys, of railway surveys and 

 profiles, of various special maps and reports published by the Geo- 

 logical Survey and by the early Government surveys, of the maps 

 and journals of the early explorers, of many private maps, both 

 pubhshed and unpubhshed, of maps and articles in the technical 

 press, etc. These data have been supplemented by about 25,000 

 miles of personal travel through the regions in question and by con- 

 ference with official and private surveyors, railway engineers, pros- 

 pectors, and others famihar with the country. It is impossible to 

 acknowledge all these sources in detail, but the writer wishes to make 

 special acknowledgment of the kindness of Prof. G. E. Bailey, of 

 Los Angeles, in tendering the use of his collection of personal maps 

 and notes of the desert basins of CaUfornia, as well as in communi- 

 cating the various conclusions resulting from his extensive travel in 

 these regions. 



The topographic data from all the sources mentioned have been 

 collected, carefully compared, and the final conclusions used in plat- 

 ting on base maps the boundaries of the various basins. From these 

 maps have been calculated the areas given in the following pages. 

 Every possible care has been used in the platting of the lines and in 

 the computation of the areas, and it is beheved that accidental errors 

 have been almost if not quite eUminated. Li nearly all cases the 

 areas as given may be considered accurate within 10 per cent and in 

 most the accuracy is far greater. In a few places, mainly in country 

 of sHght reUef and where divides are inconspicuous, the position of 

 present and past water partings remains uncertain, and the areas are 

 correspondingly open to doubt. All such cases are noted in detail 

 in the text and, in general, a perusal of the text will indicate the 

 probable accuracy and assurance of the various conclusions better 

 than could be done by any general statement. 



THE GREAT BASIN AND ITS DEVELOPMENT. 



The most important areas of internal drainage in the United States 

 lie within the so-called "Great Basin" of Utah, Nevada, and CaUfor- 

 nia. This is by no means a unit, but an area of somewhat complex 

 topography divided into a number of basins of various ages and 

 characters. In order that this topography may be the better under- 

 stood it is necessary to discuss briefly the history of its development, 

 and this is perhaps the more useful since its development has been 

 in many ways parallel to that of other imdrained areas which lie 

 beyond its borders. There is scarcely a phase of basin topography 

 elsewhere that has not its coimterpart in the Great Basin. 



