The book's explanation for the omission is that Spokane's Expo'74 was an "Environmental Fair." This was a small fair area wise, smaller than the 1962 Seattle Worlds Fair, "Century 21" which I attended.
As there are only two official medals and one trade dollar from the Expo, I can understand the omission.
Comments
Jeff's book on West Coast Exhibition SCD's did not include the the Spokane World's Fair, "Expo `74" which offered a bronze & Silver U.S. Mint Medal.

Just saw this. It might be worth contacting Jeff and Bill at their site: https://so-calleddollar.com
The book's explanation for the omission is that Spokane's Expo'74 was an "Environmental Fair." This was a small fair area wise, smaller than the 1962 Seattle Worlds Fair, "Century 21" which I attended.
As there are only two official medals and one trade dollar from the Expo, I can understand the omission.