i n i ) p: x . 
Page. 
Aa lava, view of 58 
Alluvium , occur rence of 19 
Alvord Desert, Oregon, location and char- 
acter of 33-34 
Alvord Valley, Oregon, lakes and playas 
In—. 34 
location and character of 33-34 
Andes, snow line in, altitude of 12 
Anticlines, manner in which petroleum 
and natural gas accumulate, fig- 
ure showing 74 
petroleum in, occurrence of 76 
Artesian basins, hot springs in 25-26 
location and extent of 25 
Artesian wells at Boise, temperature of . 24 
Ascension Island, bomb from structure 
of ■- 43 
Baker City, Oreg.. weather record at, for 
1900 8 
Basalt, occurrence and character of 65 
of Stein Mountain : 15 
Beulah, Oreg., fossil leaves collected near. 02 
volcanic dust near, plate showing 62 
Boise, Idaho, hot springs and wells near. 24 
weather record at, for 1900 8 
Bombs, volcanic, occurrence, shape, struc- 
ture, character, etc., of 40-45 
sections of 44 
views of 40,42 
Bowden Crater, Oregon, location, struc- 
ture, etc., of. 57-58 
Burns, Oreg., forest near _ . J 0. 1 1 
weather record at, for 1900 8 
California, snow line in. altitude of 12 
tree growth in, upper limit of 11 
Caspian Sea, loss of saline matter by 31-32 
Castlerock, Oreg., forest near 10 
Cinder Buttes, Idaho, aa lava at, view of. 58 
cinder cones of, features of 45-47 
craters among, structure of 39-40 
lapilli, cones, and bombs at, views of 40, 42, 44 
lava flows at, view of margins of 58 
location of 38 
sequence of events in 45 
tuff on lava flow at, view of 38 
volcanic bombs of 40-45 
Cinder cone, fragment of, view of . . _ 44 
Climate, characteristics of 8 
Cone, fragment from, view of 44 
Cones, view of 40 
Cow Creek Valley, Oregon, lakes in 27-28 
Craters. (See Jordan Craters; Diamond 
Craters; Cinder Buttes.) 
Bull. 217—03 6 
Page. 
Dana, J. D., reference to 45, 16,52 
Darwin, Charles, quoted on bomb from 
Ascension Island 43 
Dawson. R. H., reference to 7 
Denudation, increase in . _ 19-20 
Diamond Craters. Oregon, driblet cone at. 
view of 52 
location, structure, lava, etc., of 54-57 
pressure ridge in lava at, view of 60 
Dike rocks, occurrence and character of. 66-67 
Dikes of Stein Mountain __ 16 
Dog Mountain, Oregon, efflorescence from 
near, analysis of 36 
Domes in lava, occurrence of _ 54 
view of. 60 
Donner and Blitzen River, Oregon, course 
of 22 
Drainage, directions of 21 
Driblet cones, views of 52 
occurrence of 52 
Eolian mounds, occurrence of 33 
view of 30 
Erosion, increase in 19-20 
Fissures, effect on storage of petroleum. 78 
Forests, occurrence and extent of 9-12 
Fossils, occurrence of... 62-63 
Frost, dates of first and last, in 19C0 8 
Garnet, Idaho, weather record at, for 1900 8 
Gas, conditions favoring storage of petro- 
leum and 69-80 
physical properties of 70 
Gilbert, G. K., cited on Lake Bonneville. 34 
Grasses, effect of overgrazing on 19-20 
Grazing, effect of 19-20 
Hanging valleys, occurrence of 17 
Harney, Oreg., forest near 10,11 
Harney and Malheur lakes, Oregon, 
streams tributary to 22 
Harney artesian basin, Oregon, location, 
extent, and water supply in 26 
Harney Lake, Oregon, existence of, cause 
of.. 22 
location, area, and water supply, etc., 
of.. -. 29-32 
water from, analysis of 31 
Horizontal beds, petroleum and natural 
gas in, concentration of, figure 
showing 75 
Hot springs, location of 24 
Igneous rocks, occurrence and character 
of ----, 64-66 
Iron Mountain, Oregon, eolian mounds 
near, view of 39 
81 
