The Rushville Museum moved in to the 1890 Armstrong House in 1960. Under the leadership of Judge Benschoter artifacts that interpret the history of Rushville, Sheridan County and the surrounding trade territory were incorporated into the museum. A log cabin that had served as an early day Rushville Post Office and telephone office was added to the grounds. In the 1960s a library was added to the museum that includes area history and pre-history.

Among the displays in Armstrong House are military and Native American history of the Indian Wars era from Camp Sheridan (1874-1881) and Spotted Tail Agency (1874-1877), open range ranch history, old photographs and paintings, early day lodge and fraternal display, store items, defunct bank display, early day clothing and more. The post office/telephone office is set up as an early day home post office with the original central phone board from White Clay.

Other service available at the Rushville Museum include historical and genealogical research, historical tours by request and speakers bureau.