The White Pass & Yukon Route ran trains, ships, river boats, and–as shown in this 36-page booklet–buses in the name of its subsidiary, the British Yukon Navigation Company. Most of this booklet is printed in a green-tinted ink, but it includes eight pages of full-color photos including the cover.
The booklet does not have a definitive date, but several clues indicate it is from the late 1940s or early 1950s. The buses pictured throughout the booklet are similar to those in this 1948 brochure, which identifies them as Pony Cruisers. These were made by the Kalamazoo Coach Company between 1940 and 1951. A picture of a DC-6 on page 5 dates the booklet to after 1946. White Pass & Yukon started buying Diesels in 1954, and would have included a photo or drawing if this booklet came out in that year or later, so the booklet dates from 1947 to 1953. I suspect earlier in this range is more likely.