114 Henry Gannett — Mother Maps of the United States. 



most of the present stage of development has been produced 

 since the work of the Hayden, Wheeler, Kmg and Powell sur- 

 veys was done. 



To bring this culture element up to date on maps of the 

 two last-mentioned scales, viz, 8 and 16 miles to one inch, the 

 postal-route maps are of great service — are, indeed, well-nigh 

 invaluable. 



Summary. 



About 76 per cent of the area of the United States, exclusive 

 of Alaska, has been surveyed by the general government on 

 various scales, and fully 16 per cent more has been surveyed 

 by other organizations or private parties in such manner as to 

 yield useful maps, leaving barely 8 per cent of our territory un- 

 surveyed. The mother maps of the country are based upon 

 these surveys. 



The areas represented on the various mother maps of the 

 United States and available for compilation, classified by the 

 scales on which they are worthy of reproduction, are summarized 

 in the appended table. They are also shown graphically in the 

 accompanying map of the United States forming plate 17. 



The scale of 1 : 1,000,000, or nearly 16 miles to one inch, has 

 been adopted by the Geographic congress for mapping the earth, 

 and it is therefore of interest to know how much of this country 

 can be mapped on this scale, and where the areas are located 

 concerning which our information is too scanty to warrant such 

 representation. These areas may briefly be enumerated. They 

 are : 



Northern Maine. 



Adirondack plateau of New York. 



Southern Florida. 



Most of Idaho and much of Montana. 



The Cascade and Coast ranges of Oregon and Washington. 



Western North Dakota and South Dakota. 



Western Texas and southeastern New Mexico. 



