Though “Pacific Northwest” usually refers to just Oregon and Washington, the brochure, which unfolds into the equivalent of six pages of a standard 8″x9″ booklet, gives equal time to Montana and Idaho. It has no date, but the mention of “the famous Columbia [River] Highway” indicates it is from after 1917, when that highway was first completed. Based on the photographers, I suspect it is from the early 1920s.
Five of the photos in the brochure are by Seattle photographer Asahel Curtin. Five photos of Oregon scenes are by Portland photographer Arthur Prentiss. Two photos of Yellowstone and one of Native Americans are probably by Frank Jay Haynes, who was known as the official photographer of Yellowstone Park as well as the Northern Pacific Railway, though there is a remote chance that they could be by his son, Jack Ellis Haynes. Except Jack Ellis, these photographers did most or all of their work before 1922.