Is it legal to drive 53ft trailer with tandems all the way back?

I dont know if its legal or not but,.... I was out there in August and no one bothered me. I run an RGN 58ft long when my rear axle is down(and it was on this trip) and my axles are all the way to the rear. And my total length is about 83ft from bumper to bumper. My load was legal.

Edit to add: I ran from Mt Vernon, WA back to Virginia

 

I've seen it once on 5 in California (Stockton area)! Obviously not legal but maybe 53 dry van had a permit or a complete schmucK unaware of CA/FL laws...

 

Federal Size Regulations for Commercial Motor Vehicles - FHWA

 

It's a state thing. I have no idea how old this webpage is.

 

While your pictures and links are nice and all, it doesn't answer the Op's question for kpra laws for those specific states.
I found one listing for all states, but as Michigan was wrong on it I don't trust any other state on that list.

 

People sometimes get Bridge Formula confused with the kingpin distance rules. I remember once getting loaded in Effingham Ill with a VERY heavy pallet right on the rear end. I could not get that load legal without the back tandem being most of the way back. On my path to Texas, I was only concerned with Illinois. I was OK in Missouri, Oklahoma, and Texas.

 

This is why a driver should keep the latest copy of the trucker's atlas.

 

Well he can always call each state and ask or, look up individual state dot page.

Try to be nice and people always nit pick and complain.
If one doesn't take the time to do the work themselves, how will they ever learn.