Also you should all know that the grade from Laughlin (actually it's Bullhead City) up toward Kingman is the de-facto SAE test grade for trailer tow tests conducted by the auto OEM's. This grade is commonly called "Davis Dam Grade". On any given day during the hottest summer months you'll find them there towing huge loads up that grade. It's what I do!
OEM Auto Engineer 2003 Damon Challenger 348 Class A - F53 Triton V10
2006 Jeep Grand Cherokee Limited 4x4 V8 Toad