The Sagebrush Roundup was radio station WMMN's response to the growing popularity of live-audience country music jamborees in the pre-World War II years. Modeled after the WWVA's Wheeling Jamboree, Nashville's Grand Ole Opry and similar programs, the Roundup began in December 1938, originating from the National Guard Armory in Fairmont, West Virginia. Notable performers included Cowboy Loye Pack, Cherokee Sue and Little John Graham, Blaine Smith, Budge and Fudge Mayse, Jake Taylor, Buddy Starcher, and Grandpa Jones, the latter two of whom went on to attain national reputations. The Roundup remained popular for several years. During the war, performers such as Wilma Lee and Stoney Cooper and Lee and Juanita Moore made their base at WMMN.

In 1947, WPDX Clarksburg began seriously competing with WMMN for the country music market in northern West Virginia. By 1948, only Jake Taylor's Railsplitters and Hank the Cowhand (David Stanford) and his Foggy Mountain Gang remained on the Roundup roster. The last Sagebrush Roundup broadcast took place on October 2, 1948. However, the name remained in use into the early 1950s on daytime programs featuring Hank the Cowhand and Blaine Stewart. Since 1985, a revival of the fondly remembered program has been held at Bunner's Ridge near Fairmont, and has featured guest appearances by Wilma Lee Cooper, Little John Graham, and Buddy Starcher. The new Sagebrush Roundup consists of Saturday night concerts which are not broadcast.