Where to put the litter box so it's out of sight, and out of reach of the dog?

Not 100% sure which type of travel trailer I'll be living in, but I'm not seeing a lot in the way of floor level cabinets that I can install a cat flap on.

Anyone else lived with cat(s) in an RV, full or part time?

LDG definitely has. You may want to PM her. :)

Totally forgot about her, thanks :)

I live in an RV full time (very very very hard to get a place to live in Lower BC if you have any pets). As we are space restricted but don't move the motorhome a lot we keep the front cab area for the litter box. It's out of the way but easy to get at, the cat has access and privacy. I recommend a covered box if you can fit it in, use high quality litter and change your carbon filter regularly too. The air in an RV goes off faster than in a house and since the kitchen and living areas are all of a piece you need to stay on top of the box more than in a house! MacBeth has had this arrangement for all of his 3 years and he's been fine.

Having finally come to terms with the fact we won't be getting four walls and a roof any time soon we plan to upgrade our RV to a larger fifth wheel and when shopping I will be keeping litter box placement in mind!