ILLUSTRATIONS. Page. PLATE I. Crest of Bitterroot Mountains.... 16 II. A, Cabinet Range; B, Summit of Cabinet Range, showing points 18 III. A, Camp south of summit of Cabinet Range; B, Quartzite slate near summit of Scotchman Peak. IV. Astronomic piers in court-house grounds at Spokane, Washington. V. Diagram of triangulation for control of the Idaho-Montana boundary... VI. Transit station on random line. VII. Granite boundary-line monuments VIII. Design for iron post.. - - 2220 IX. Post 48, at summit of timbered ridge. X. Post 42, and line cut through timber XI. A, Granite monument on boundary line near Leonia, Idaho; B, sectional monument at summit of Bitterroot Mountains.. XII. Clark Fork of Columbia River just west of boundary line. XIII. Summit of Bitterroot Mountains, showing pack train loaded with sections of granite monument 54 56 XIV. Map of boundary line. FIG. 1. Design for stadia rod. LETTER OF TRANSMITTAL. DEPARTMENT OF THE INTERIOR, UNITED STATES GEOLOGICAL SURVEY, Washington, D. C., February 21, 1900. SIR: I have the honor to transmit herewith a detailed report relating to the survey of the boundary line between Idaho and Montana from the internaţional boundary to the crest of the Bitterroot Mountains. I wish to make acknowledgment of the valuable services rendered in this connection by Messrs. S. S. Gannett and D. L. Reaburn, in field and office, and by Mr. E. T. Perkins, jr., in the field. Mr. Gannett prepared the greater portion of the material relating to latitude, longitude, base line, azimuth, and triangulation. Very respectfully, RICHARD U. GOODE, Geographer. Director United States Geological Survey. Hon. CHARLES D. WALCOTT, |