The city of Gillette, Wyoming calls itself "The Energy Capital of the Nation", as it produces over 35% of the nation's coal as well as oil and methane gas, and has experienced a massive population growth over the past decade. Just shy of its 125th birthday (on January 6, 1892) the city arranged for a pictorial postmark.
For these covers from @McGeekiest Cachets, I chose a photograph of a herd of bison outside the city limits. I applied a filter to make the photo seem like a watercolor painting. Two Wyoming State Centenary stamps from 1990 (Scott #2444) are positioned at the top of the cover and are postmarked with a "Gillette, Wyoming: Celebrating 125 Years" pictorial postmark from Gillette, Wyoming, 82716 dated August 27, 2016.