F350 Super Duty vs 3500 Denali vs The Ike Pulling 30k lbs

This website will help you find the grade of that road. It is made for cycling, but you can select to follow the road. You will have to select start and the click the where you want to start on the road and then click again where you want to end. Then select show elevation and gradient to see those.

If this is the road then Cummins is right. It even gets steeper than 14% in some areas.

Mapometer