(Cyclone, IA-12-40) E. of Shell Rock, Jefferson Township, Butler County, IA. Butler Center Rd. W. 4.1 miles from jct with Cherry St. SW of Shell to the quilt on the S. side of the road at 27924. Monica Lursen. (N42 41.945 W92 40.467) Photos by Jack & June Schmidt 7-9-12.