Brad, the last Saddle Sore1000 I rode was during an Iron Butt Association International Meeting in Denver. From Glenwood Springs to Denver it was raining and cold (and naturally I didn't have my heated jacket). My GPS said that I would have ridden 1,003 miles when I go to the finish. The IBA goes by odometer reading, not GPS mileage, and it helped knowing that I'd have 1,002 miles on the odometer. If I hadn't known the accuracy of the odometer, I would have had to ride at least another 8 miles to get a receipt that would say I had passed the hotel and the finish line and then ridden back.