The Chase County Courthouse - Cottonwood Falls, Kansas. This courthouse is the oldest operating courthouse west of the Mississippi River and is listed on the National Register of Historic Places.  Built 1872-1873, this French Renaissance building constructed of native limestone  this beautiful building is something that you will want to visit while in Kansas. The structure was built at a cost of $42,599.88. The first courthouse was a small log building near the present high school. Kick off the holiday season by celebrating the holidays in Chase County on Saturday November 29th. Visit some of Chase County’s finest homes. Location: 300 Pearl, Cottonwood Falls, KS 66845.