All states and provinces accept whatever your home province/state law is. For example, if you were from Florida, where no endorsements are required, and in Ontaio, no problem. On the other hand, if you were a resident of Ontario and were operating an air equipped vehicle without an endorsement. you will be fined $1,000.
California, similar to Washington state, exempts motorhomes (as Housecars) up to 40' in length, with the standard drivers' license, and you can still tow a trailer (or another vehicle) to a maximum combined length of 65'. There is a weight limit on trailers being towed based on the weight of the towing vehicle. For California's details, go to CA DMV Website.
2008 Itasca Meridian 37H, All. 3000MH (6-auto), Freightliner XC Chass., Cummins 6.7L Turbo, (Sweet! Delivery 03/12/08). Tow: '07 Dodge Gr. Caravan, Me, Him; Sugarbear, Apr. Toy Poodle; Pepe, Blk Toy Poodle; Hero, fat Siam.-mix polydactyl cat/Alarm Clock.