In the 1880s, in conjunction with the building of the Northern Pacific Railroad, coal was discovered and the cities of Roslyn and Cle Elum were founded. Between 1886 and 1929, coal miners representing over 20 different nationalities worked and lived in the Upper County. In 1963 the last coal mine closed and the area's most important industry became logging, which had been expanding since original settlement.

The Upper County has three museums that depict area history. Because of the rich ethnic background, the area still celebrates and honors its past.