In 1918, the Diagonal Trail Association sought to register their route with the Iowa State Highway Commission (ISHC). Unlike most registrations at the time, this route was registered as a highway trail, rather than a highway route. This meant there was much less information required for registration.
The route logo was a black square on a white background with a narrow white band cutting diagonally across the black from the top left to the bottom right.
The registration application was signed by Sheridan Babcock, president of the Diagonal Trail Association, and H.B. Hall, secretary, and dated Nov. 6, 1918.
The ISHC approved the application Dec. 4, 1918. The Diagonal Trail extended from Danville, Ill. to Sioux Falls, SD. It traversed Iowa through the communities of Davenport, Iowa City, Cedar Rapids, Vinton, Grundy Center, Iowa Falls, Clarion, Emmetsburg, Spencer, Spirit Lake, and Rock Rapids.
As soon as the route was registered, confusion began to spread rather quickly throughout Iowa concerning the activities of the route association. Letter after letter was sent to the ISHC requesting a list of the officers of the Diagonal Trail Association so they could address the issues, including those with their highway markings.
A little more than a year later, it seemed as though the Diagonal Trail Association had disbanded as highway markings were not being maintained in any of the counties through which the route passed. Any attempts to contact the association seemed pointless and signs became so faded that motorists could not make out the logo to know what road they were on.
In 1924, new light was shed on the Diagonal Trail Association activities when markings in Linn County were refurnished. However, this was the only county where this occurred, so it was never confirmed whether this was the work of the association or simply a resident of the county that grew tired of the worn signs.
The notion the association was still active sparked another wave of letters sent to the ISHC asking for the associations contact information. Once again, however, any attempts to contact the association seemed futile.
By 1930, the ISHC officially deemed the association disbanded. This same year, the ISHC began receiving letters accompanied by large sums of money, some in excess of $450, to be contributed to the National Diagonal Highway to help with highway marking. There was not at the time, however, a route registered under that name; and so instead of assuming that the contributors simply misunderstood what name the route was registered under, the ISHC simply returned the money it received.
Although the association no longer existed, the route saw considerable use and was an important contribution to Iowa’s highway system.