The cover sports the cache of the official logo of the Wyoming Bicentennial Commission honoring "The Spirit of '76 In the American West!" The cover is stamped with the 3 cent Wyoming Statehood 50th Anniversary stamp (Scott #897), the 8 cent American Revolution Bicentennial stamp (Scott #1432), and the 13 cent Interphil stamp (Scott #1632). The cover was originally canceled in Centennial, Wyoming, on July 4, 1973. It was later canceled on July 4, 1976, in Centennial.
Centennial, Wyoming, was named in 1876 in honor of the 100th birthday of the United States and is the only town in the United States with that name.
The silver medal shows a little tarnish. The discoloration in the picture is reflection off of the protective plastic sleeve covering the silver bar. .