Iowa State Route 27 runs north-south along Interstate 35 from the Worth/Cerro Gordo County Line to near Clear Lake. South of Clear Lake, IA St Rt 27 runs east-west with U.S. Rt. 18 along a expressway from Interstate 35 to the Cerro Gordo/Floyd County Line. IA St Rt 27 is does not pass through any towns in Cerro Gordo County. IA St Rt 27 is multi-plexed in Cerro Gordo County. Interstate 35, from the Worth/Cerro Gordo County Line to near Clear Lake.
U.S. Rt. 18, from near Clear Lake to the Cerro Gordo/Floyd County Line.
A junction marker on WB BUSN U.S. Rt. 18/IA St Rt 122. A BGS on SB I-35; EB U.S. Rt. 18; SB IA St Rt 27. SB I-35; EB U.S. Rt. 18; SB IA St Rt 27 near Mason City. EB U.S. Rt. 18/SB IA St Rt 27 at the interchange with I-35. This is a incomplete interchange. It is set for a westward extention of the expressway. EB U.S. Rt. 18/SB IA St Rt 27 on the future colector/distributor lanes for the interchange with I-35. EB U.S. Rt. 18/SB IA St Rt 27 south of Mason City. EB U.S. Rt. 18/SB IA St Rt 27 southeast of Mason City.
