The Manthei Ford Garage is located at 350 Main Street W in the center of downtown Maynard, Iowa. In January 2006, the Iowa Department of Transportation (IA DOT) contracted the Iowa Highway Archaeology Program to conduct a Phase I investigation of a stone culvert. Marlin R. Ingalls, who conducted the study, concluded that the garage was eligible for listing in the National Register of Historic Places under Criterion A as an "important example of an early Fayette County and Iowa Highway Commission era of automobile transportation." The IA DOT contracted The Louis Berger Group, Inc. to complete this Iowa Historic Property Study to mitigate any potential damage to the Manthei Ford Garage that may occur during construction. At the time of the Phase I investigation, water from the creek had already damaged a piling on the building.