Sources generally agree on its location and identity as a relay station and a stage station.  The station, constructed as a ranch house in 1857, was known as both Hollenberg and Cottonwood because Gerat Hollenberg managed the station operations near Cottonwood Creek. The station served as the last Pony Express stop in Kansas. Hollenberg's station also supplied emigrants with food, clothing, livestock, and a place to rest themselves and their horses. The relay station is possibly the only unaltered Pony Express building on an original site.  It also served as a stagecoach stop on the C.O.C. & P.P. Express Co. stage line. 

In 1941, the Kansas State Legislature purchased the station and the surrounding acreage to preserve the site.  The Kansas State Historical Society manages the site today, and it is listed as a National Historic Landmark.

http://www.nps.gov/parkhistory/online_books/poex/hrs/hrs4b.htm