Play - "Big" The Musical Rushville - Plains Theatre July 1-4 and July 8-11, 2010 Friendly Festival Hay Springs August 26 - 27 -28, 2010 Willow Tree Festival Gordon September 11 & 12, 2010   Historical Sites and Markers Simply put, if you love history, you'll love Sheridan County. Antioch - Potash Boom Town Antioch City of Gordon Gordon City of Hay Springs Hay Springs Flying Heart Ranch Hay Springs Heritage Center Museums Hay Springs Mari Sandoz Historical Marker Ellsworth - Gordon Plains Theatre Rushville Scamahorn Museum Gordon Sheridan County Historical Museum Rushville Spade Ranch Ellsworth Spade Ranch Historical Marker Ellsworth Tri-State Old Time Cowboys Memorial Museum Gordon Wade Morgan's Cowpoke Haven Ellsworth