Hollenberg Pony Express Station, also known as Cottonwood Pony Express Station, was built by Gerat H. Hollenberg in 1858, to serve travelers on the Oregon and California Trails. When the Pony Express was established in 1860, the cabin served riders and provided remounts. The station also served the Butterfield Overland Mail. Hollenberg traded with emigrants on the trails, operated the westernmost Pony Express station in Kansas, and provided relay services for the Overland Mail. The building has never been moved and retains its original dimensions. Hollenberg prospered, establishing the town of Hanover, Kansas and winning election to the Kansas Legislature.