I and @hmknightnc are the same page with axle and GCVW. I have an F450 (16500 GVW) due to the weight of my bunkhouse trailer ( it has 3 slides) and I pull a small boat behind it. My trailer has a heavier tongue weight then the manufacture claims. Loaded, the hitch weight is over 4K (easy). I had a F350 crew cab dwly prior to the F450 and it was almost too much for it. The trailer would push it around. I spent a lot of money to make it safe.... but legal??? Not so much.
Getting pushed around by the trailer in the wind or when you loose a tire and you have to fight to keep the rubber side down.....I'm jus sayin....
On yellowstone, you are ok with a trailer 40 ft or under. My trailer is 36.5 ft. Long, not counting the hitch or bumper, and it is hooked to a crew cab long bed. It is tight at Fishing Bridge and some people have a hard time backing in ( but you are not going there) as it is at most CG's in YS. We have never had an issue with being over 50 ft total. Only once did the camp host walk out to look at the length and all he did was look at the factory sticker that says 33'TBH. But that is just the model number and that's all I have had anyone, anywhere check.
Madison CG has some that can take a large rig and it is a cool CG. No hook-ups but campfires are ok.
P.S. I saw you are from Cal, too ( SoCal for us). We make the trip to YS every 2 to 4 years and are planing a trip next year also. Have a good trip next year, we love the place.
