ILLUSTRATIONS. 



Page. 



PLATE LXXXVII. General map of the lower Snake River Valley, Idaho-... 625 

 LXXXVIII. Head of Boise Valley, 8 miles southeast of Boise, look- 

 ing northwest, showing basalt table and Pleistocene 



terraces 632 



LXXXIX. Upper canyon of . Brainard Creek, Jerusalem Valley, 

 Boise Ridge, showing tilted basalt flows resting on 



granite 636 



XC. Types of gold-bearing fissure veins GoO 



XCI. The Idaho Basin, looking east from the Jerusalem Road 



west of Quartzburg __ 656 



XCII. Lower Valley of Moore Creek, 3 miles above its mouth, 



showing basalt flow cut through by the creek 658 



XCIII. Idaho City from Gold Hill, looking southwest, showing 



tailings and bench gravels 660 



XCI V. Working bench gravels by the hydraulic process at Idaho 



City 662 



XCV. Gravel bank with underlying lake bed at Plowman's 



claim, East Hill, Idaho City, looking southwest 664 



XCVI. Geological map of the Idaho Basin In pocket 



XCVII. Map of the Neal mining district, by F. D. Howe 700 



XCVIII. Map of the Willow Creek and Rock Creek mining dis- 

 tricts 708 



XC1X. Fossil leaves, Pay ette beds 738 



C. Fossil leaves, Payette beds 740 



CI. Fossil leaves, Payette beds 743 



GIL Fossil leaves, Payette beds 744 



FIG. 55. Gravel benches, 1 miles below Idaho City 681 



56. Section of highest bench, 1 J miles below Idaho City 662 



57. Section across lake beds and gravels at Idaho City 663 



58. Exposure of lake beds and auriferous gravel, l miles south of 



Idaho City. 665 



59. Bench gravel and lake beds at mouth of Granite Creek, 2 miles 



west of Idaho City 666 



60. Bank of bench gravels, one-fourth mile north of Pioneerville, 



level of Grimes Creek 671 



61. Bank at the Ranch Company's claim, Placerville 674 



62. Diagram of fault in the Cleveland vein 686 



63. Section of Mountain Chief vein, east end of claim 690 



64. Breast of drift, Carroll vein 693 



65. Cross section of vein in the Neal mining district 701 



623 



