ILLUSTRATIONS 
Page. 
Plate I. Map of United States, showing location of geologic field parties in 
1903 .- 28 
II. Geologic map and section of the region around Telluride, Colo., 
illustrating the method of representing geologic formations 30 
III. Map of Alaska, showing progress of geologic and topographic recon- 
naissances and special investigations 46 
IV. Map of United States, showing locations of topographic field parties 
in 1903-4 62 
V. Map of United States, showing areas covered by topographic surveys. 64 
VI. Map of United States, showing condition of astronomic location and 
primary control on January 1, 1904 .■ 70 
VII. A, Typical bridge gaging station— Mississippi River at Anoka, Minn. ; 
B, Typical cable gaging station — Milk River at Havre, Mont 82 
VIII. A, Apparatus for rating current meters at Chevy Chase, Md.; B, 
Typical weir gaging station, Los Angeles River, California 84 
IX. Price electric current meters, with buzzers 84 
Fig. 1. Ideal view and corresponding contour map 58 
2. Map showing locations of river stations and principal irrigation proj- 
ects in western half of United States in 1903-4 80 
, 3. Map showing locations of river stations in eastern half of United States 
in 1903-4 81 
4. Map showing progress of work on underground w T aters in western half 
of United States in 1903-4 86 
5. Map showing progress of w r ork on underground waters in eastern half 
of United States in 1903-4 87 
5 
