A report on Montana deposits that provided essential optical material during the early years of World War II.

“An epic story, filled with an unfolding array of evocatively described landscapes and sharply drawn, unforgettable people.” —Dayton Duncan, writer and pr

1919/28 cumulation includes material previously issued in the 1919/20-1935/36 issues and also material not published separately for 1927/28. 1929/39 cumulation