Modern Vespa

How did you map out your Ironbutt run? I looked at mapquest and google maps, but how do you get an accurate mileage. Example: riding from Fargo, ND on I29 to Sioux Falls, SD, then going east on I90. If you mapquest Fargo to Sioux Falls, the mileage is more then if you put in an exact address at the intersection, and how do you do a map without and exact address?
Thanks for your time and Happy Thanksgiving.

I used a GPS. I picked a town that was about 500 miles away and got directions to the city center from my house. I came back by the same rout. The town that I chose was 512 miles away which gave me a little cushion. When I recieved my certification. Thier calculation was exactly the same as mine. If you want any advice let me know, Good luck. Tell us about it when you do it.

For cycling I use these two and accuracy is excellent.

Bikeroutetoaster.com
Mapometer.com

Try the tutorial on Google maps. It's pretty straightforward to just drag the line around where you want it to go. PM me if you need more info.

I joined in with an official Iron Butt ride, with specific waypoints (you needed a receipt either from the specified petrol station or somewhere else in the same town). But the route I drew on Google Maps was pretty accurate too.