Navigating the road system along Western Skies Scenic Byway

As you drive along Western Skies Scenic Byway, you may not realize how the road systems are laid out across the landscape. The system starts in 1785, decades before Iowa was a state. “The Land Ordinance of 1785 was passed by the U.S. Congress under the Articles of Confederation. It laid out the process by which lands west of the Appalachian Mountains were to be surveyed and sold. The method of creating townships and sections within townships was used for all U.S. land after 1785” (Source: State Historical Society of Iowa).

According to USGS, “The Public Land Survey System (PLSS) is a way of subdividing and describing land in the United States. PLSS surveys, which are available for portions of land in 30 southern and western states, are made by the Bureau of Land Management (BLM). The PLSS typically divides land into 6-mile-square townships. Townships are subdivided into 36 one-mile-square sections. Sections can be further subdivided into quarter sections, quarter-quarter sections, or irregular government lots.”

As you drive east-west or north-south, you will typically cross a county gravel road every mile. There are some exceptions, however, such as when a river or other geologic feature creates a challenge to this grid, or where roads have been closed due to lack of local traffic. In some cases, the roads are still open but have become minimum-maintenance dirt roads.

The Homestead Act of 1862 gave settlers 160 acres of land for free with the requirement that they farm the land for at least five years. This act used the PLSS with sections of 640 acres; quarter-sections of 160 acres, and “forties” of quarters of quarters. If you’ve ever heard the term “the back forty,” it’s a reference to this system!

While a grid is easy to understand, it faces some challenges in the rolling topography of western Iowa. This “system has necessitated greater expenditures for such rural services as highways, telephone and power lines, mail delivery, and school-bus routes. In rough, dissected areas it has posed problems in the layout of transportation lines, and it has encouraged farmers to lay out their fields against the grain of the country, to the dismay of conservationists” (Source: John Fraser Hart, The Rural Landscape, p. 155).

Imposing a grid of straight lines is difficult on a sphere, so “correction lines” were established within the PLSS grid. “A township line established every 24 miles north and south of the baseline as part of the U.S. Public Land Survey System and Canada's Dominion Land Survey. Surveyors created correction lines where they readjusted range lines to compensate for the convergence of meridians.” 

For a more detailed explanation of this system, check out this post.​

Harrison County township & range map. Source: https://iagenweb.org/harrison/twp/rangemap.htm

The county road system in each county is based on the mile-by-mile grid with numbered and named roads running perpendicular to each other:

• In Harrison County, north-south roads are alphabetical from west to east: Boone, Britt, Cook, Delta...to Toledo, Upland, Vienna. East-west roads are numbered from north to south: 110, 120, 125...to 315, 325, 335.
• Shelby County's north-south roads are alphabetical from west to east, named after trees and plants: Apple, Beach, Cedar...to Yellowwood, Yucca, Zinnia. East-west roads are numbered from south to north: 100th, 200th, 300th...2300, 2400, 2500.
• In Audubon County, north-south roads are alphabetical west to east, named after birds: Bluebird, Crane, Dove...to Quail, Robin, Swift. East-west roads are numbered north to south: 100, 110, 120...through 330, 340, 350. 
• Guthrie County's north-south roads are alphabetical west to east, named (mostly) after trees : Chestnut, Cherry, Dogwood...Victory, Wood, Yellow. East-west roads are numbered north to south: 100th, 110th, 120th... to 330th, 340th, 350th.​ 

example of roads system in Audubon County. source: https://iowadot.gov/maps/msp/pdf/audubon-co.pdf

At a higher level, the county highway system in Iowa has its own arrangement. The tier of counties where Western Skies lies includes east-west roads starting with the letter “F,” and north-south roads ranging from “K” in western Harrison County to “L” in most of Harrison County, “M” in Shelby County, “N” in Audubon and Guthrie counties, and “P” in eastern Guthrie County. If you are driving on F-16, for example, you can know that you are traveling on an east-west road.