Iowa Highway 188
|Maintained by Iowa DOT|
|Length:||24.231 mi (38.996 km)|
|Existed:||1945 – present|
|South end:||Iowa 3 near Clarksville|
|East end:||US 63 near Tripoli|
Iowa Highway 188 (Iowa 188) is a state highway in north-central Iowa. The route is signed both north-south and east-west because of a 90-degree corner near the route's midpoint. The route begins at Iowa Highway 3 south of Clarksville and ends at U.S. Route 63 near Tripoli.
Iowa Highway 188 begins at a T intersection with Iowa Highway 3 2 1⁄2 miles (4.0 km) south of Clarksville. From Iowa 3, Iowa 188 heads north where it crosses the Shell Rock River and forms the eastern boundary of Heery Woods State Park. It passes through Clarksville and continues north for 4 miles (6.4 km). At four-way intersection with Butler County Road T64 and a gravel road, Iowa 188 turns to the east and becomes an east–west road for the remainder of its journey.
Iowa 188 heads east for 6 miles (9.7 km) where it crosses into Bremer County one mile (1.6 km) west of Plainfield. One half-mile (0.8 km) into Bremer County, is a diamond interchange with U.S. Route 218 and Iowa Highway 27, the Avenue of the Saints highway. In Plainfield, Iowa 188 crosses over the Cedar River. It continues due east for 10 miles (16 km), ending at U.S. Route 63 north of Tripoli.
Iowa 188 was designated in 1945 as a 10-mile-long (16 km) route which connected US 218 at Plainfield to US 63. It first appeared on the state highway map in 1946. Four years later, the highway absorbed Iowa 53, which connected Clarksville to Iowa 10. Until 1963, the highway appeared very much like it does today. That year the section of highway between Clarksville and Plainfield was turned over to Butler County officials and the section south of Clarksville became Iowa 122. Just three years later, the Iowa State Highway Commission changed course and reabsorbed Iowa 122. Since then the routing has not changed.
|Butler||Jackson Township||0.000||0.000||Iowa 3|
|Fremont Township||7.200||11.587||CR T64||Iowa 188 becomes an east–west route|
|Bremer||Plainfield||13.711||22.066||US 218 / Iowa 27|
|Douglas Township||24.231||38.996||US 63|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi
- Iowa Centennial Highway Map (PDF) (Map). Iowa State Highway Commission. 1946. Retrieved June 6, 2011.
- "2009 Volume of Traffic on the Primary Road System of Iowa" (PDF). Iowa Department of Transportation. January 1, 2009. Retrieved July 5, 2010.
- Official Highway Map of Iowa (PDF) (Map). Iowa State Highway Commission. 1950. Retrieved June 6, 2011.
- Iowa State Highway Map (PDF) (Map). Iowa State Highway Commission. 1964. Retrieved June 6, 2011.
- Iowa State Highway Map (PDF) (Map). Iowa State Highway Commission. 1967. Retrieved June 6, 2011.