(July 1, 1920-April 1930)
- In 1920, they knew it as: A last-minute isolation of Rock Valley from the North Iowa Pike
- We know it as: US 18 between Rock Valley and K42
- Let's get granular: 14th Street and 28th Avenue/Fig Avenue in Rock Valley, then 2 miles of US 18
- The Creek Boulevard cutoff between 14th Street and 18 was built ca. 1922.
WEST End: Rock Valley, Sioux County
Two towns served by spur routes in the 1920 system have a population above 2200 today: Bondurant and Rock Valley (1920 pop. 1347, 2010 pop. 3354). Rock Valley is in the pocket of northwest Iowa that in recent decades has defied the rural decline.
EAST End: IA 19/IA 22, now US 18 at K42, Sioux County
"It was decided that the routing from Milwaukee to Prairie du Chien be Route No. 19, also that the routing from McGregor, Iowa, to Sioux Falls, S.D., to be the same as the original North Iowa Pike except the small section west of Perkins, this to be routed via the primary road thru Doon and Inwood to Canton instead of via Rock Valley." — Sioux County Index (Hull), August 15, 1919
The North Iowa Pike had come into Rock Valley and then gone north via K30, 270th Street and Eagle Avenue to A42. This change unified the east-west and north-south routes south of Doon.
Page created 4/1/20; last updated 9/7/20