82 
INDEX. 
Page. 
Jordan Craters, Oregon, domes in lava at, 
view of ™ 
driblet cone at, view of 52 
lakes caused by lava flow fr< >m 27 
lava gutters at, view of ,;n 
location, age, structure, character, 
etc., of .- - -- : ; ; )4 
pahoehoe lava at, view of 58 
Jordan Creek, Oregon, craters near 48 
Jordan Valley village, lakes near 27 
Juniper, occurrence of. - 9 
Keiger Creek Canyon, Oregon, features of 16-17 
Knowlton, P. EL, quoted on fossil plants. 02 
Lake beds, exposures of, plate showing. . 62 
occurrence of 1 s_1 i( 
Lake Payette, Oregon, fossil leaves from. 62 
Lakes, efflorescences left by 35-36 
fluctuations of 34-35 
location of : -' :;il 
Lapilli, island of, view of 40 
La va, varieties and manner of extrusion of 37 
Lava flows, view of margins of - - 58 
Lava gutters, occurrence and character of 52-53 
views of - 60 
Lava streams, tuff floated on 39-40 
Lewis artesian basin, Idaho, location, 
area, and water supply of . . 25 
Lindgren, Waidemar, reference to 61,63 
Mahogany Mountain, Oregon, location 
and structure of 14 
Malheur and Harney lakes, Oregon, 
stream in region of, draining to._ 22-23 
Malheur Lake, Oregon, existence of, 
cause of 22 
location, area, and water supply, etc., 
of 29-32 
view of soxith shore of 30 
Malheur River, Oregon, former channel 
of 22 
Mexico, tree growth in, upper limit of . . . 11 
Mineral resources, description of 69-80 
Mountains, structure, extent, etc., of .13-17 
Mule, Oreg.,lava dam, former channel of 
Malheur River near 22 
Narrows, Oreg., efflorescence from near, 
analyses of 36 
Newberry, J. S., quoted on life in Terti- 
ary period 63-64 
Orton, Edward, reference to 76 
Otis artesian basin, Oregon, location and 
area of 25-26 
" Ovens," occurrence and character of .. 52 
Owyhee Mountains, structure of 14 
Owyhee River, Oregon, course of, rocks 
exposed on, and reservoir site on. 21 
Tertiary lake beds on, plate showing. 62 
Pahoehoe lava, view of 58 
Payette, Idaho, weather record at, for 
1900 8 
Payette formation, extent and character 
of 61 
Petroleum, conditions favoring storage 
of 69-80 
physical properties of 70-71 
source of. 72 
Pickles Butte, Idaho, petroleum at, pos- 
sible occurrence of 79-81 ) 
Page. 
Playas, occurrence of 32-33 
Porosity of rocks, effect on storage of pe- 
troleum 71 
Pressure ridge in lava, occurrence of 54 
view of 60 
Rainfall, amount of 8 
Rhyolite, occurrence and character of . .. 65-66 
Ridge in lava, occurrence of 54 
Rim rocks, occurrence of 13 
weathering of plate showing 60 
Rocks, porosity of, effect on storage cf pe- 
troleum 71-72 
subdivisions of (JO 
Russell, I. C, cited on laker, 34 
cited on recent volcanoes 36 
Sagebrush, occurrence of. 9 
St. Elias, Mount, Alaska, snow line on, 
altitude of 12 
tree growth on, upper limit of 11 
Sedimentary rocks, occurrence and char- 
acter of 60-64 
Sheep, overgrazing by, effect of 19-20 
Silver Creek Valley, Oregon, lakes and 
playas in... 32 
Silver Lake, Oregon, location of 32 
weather record at, for 1900 8 
Silver Lake Valley, Oregon, vegetation in 33 
Silvies River, Oregon, course of 22 
source of 10 
Snake River, Idalio, tributaries of 21 
Snake River Plains, Idaho, extent and 
character of 12-13 
Snake River Valley, Idaho, petroleum in, 
search for. 69 
Snow, amount of 8 
Snow line, altitude of 12 
Springs, hot, locations of 24 
temperature of 23-24 
Steiger, George, analysis by 31,38 
Stein Mountain, Oregon, anticline in 68 
basaltof ,. 65 
basins east of 23 
dikes in 67 
location, 'structure, and stratigraphy 
of 14-16 
tree growth on 1 1 12 
Streams, character and occurrence of 21-23 
Structure, discussion of 67-69 
Temperature, record of 8- 
Tertiary formations, occurrence and ex- 
tent of .-. 59-67 
Tertiary lake beds, exposures of plate 
showing 62 
Tertiary lakes, deposits of 18-19 
Tertiary period, climate, topographic and 
f aunal conditions during 63-64 
Timber line, occurrence and altitude of.. 10-12 
Topography, features of 12-20 
Trees, growth, upper and lower limits of 10-12 
Tuff , crags of , view of 38 
Turner, Scott, reference to 7 
Vale, Oi'eg. , hot spring at, temperature of 24 
weather record at, for 1900 8 
Valleys, character and extent of 12-13 
deposits in, features of. 18-20 
hanging, occurrence of 17 
Vegetation, characteristics of 9-12 
