DEPARTMENT OE GEOLOGY 3Y 
Geological and relief map of the Henry mountains showing 
effects of erosion. 
This is on a larger scale than the preceding map and shows 
only a portion of the same territory. 
Same as the above, ideally restored before erosion took 
place. 
Model showing Henry mountains and vicinity ideally re- 
stored before erosion took place. 
This is on the same scale as the first of the series. 
The foregoing series of four maps illustrates the formation 
of laccoliths or dome-like mountains produced by the intrusion 
of lava. 
Relief map of Yellowstone National Park, showing canyons 
of the Yellowstone and Madison rivers, etc. Horizontal and 
vertical scale, 1 inch equals 1 mile, or 1 : 63,360. 
Relief map of the Yosemite Valley from surveys made by 
Captain of Engineers, George M. Wheeler, U. S. A. Scale, 1 inch 
equals 1,000 feet. 
Relief map of Eureka District, Nevada, colored to show 
geological formations. Scale, 1 inch equals 16,000 feet. 
Relief map of the island of Porto Rico. Horizontal scale, 
1 inch equals 4 miles. Vertical scale, 1 inch equals 2 miles. 
Relief map of the Hawaiian Islands. Horizontal scale, 1 
inch equals 4 miles. Vertical scale, 1 inch equals 2 miles. 
Relief map of the Niagara river. Horizontal scale, 1 inch 
equals 1 mile. Vertical scale, 4 : 1. The entire course of the 
Niagara river is shown. 
Relief map of Niagara Ealls and vicinity on a larger scale 
than the preceding. Horizontal and vertical scale the same, 
1 inch equals 500 feet. This map, besides exhibiting the famil- 
iar features of the Ealls and Gorge, also makes plain the ancient 
shore of Lake Erie and the old channel leading from the Whirl- 
pool. 
Relief map of the United States and the Gulf of Mexico, 
modeled on a section of globe 16l4 feet in diameter. Horizontal 
scale, 1 inch equals 40 miles. Vertical scale, 1 inch equals 8 
miles. This map is colored to show average annual rainfall and 
lines of equal temperature. 
Relief map of the Grand Canyon of the Colorado and the 
cliffs of southern Utah, colored to show geological formations. 
