Into the hostile camp, [331]

Introducing high-grade horses and cattle, [176]

Irrigation, natural sub-, [6]

Isaac I. Stevens' survey for railroad, [162]

Isaacs, H. P., [149]

Isaacs, J. C., [149]

Itemized expense of wheat crop, [183]

Jaussaud, Leon, [180]

Jay Cooke & Company, [163]

Jefferson's instructions to Captain Lewis, [33]