Not sure about the TransAm, but Northern Tier has Chilkoot Hill in Stillwater, Minnesota. It's a three-block stretch of 24% climb. It rises 100 feet over a distance of 700. There is an annual professional cycle race in Stillwater which includes this hill (Nature Valley Grand Prix). The first year, organizers tried to put pedestrian fencing on Chilkoot but it was sliding to the bottom. So this section during the race has a European feel w/o fencing.
ACA may want to consider mapping around Chilkoot.
Can you be more specific about the location of Chilkoot Hill in Stillwater?