How to terminate a circuit
As in the answers above, there are outdoor rated panels made specifically for RVs. The image below is just one example. You should choose the appropriate panel which is rated for the needs of your RV. If you are thinking of trading up to an even bigger RV in the future, you should take that into consideration as well.



These must be mounted to a fixed location such as on the outside of a building, or on a post/pedestal. The panel below will supply enough power for the entire RV, including the appliances.

Getting back to your original question, you could either use a panel mounted to a post, or a pedestal. The advantage to the pedestal is that it is directly buried in the ground and the installation is a little cleaner. If you don't mind the looks of a post with a conduit coming out of the ground to the box, then it would be a good idea to go with a post since the pedestal is more expensive.

Keep in mind that you should probably consult a licensed electrician for the actual hookup. The long distance from the panel will require a substantial feeder from the main panel. The run will also need to either use wire rated for direct burial and/or run inside of conduit. The sub panel will also need to have independent ground rods which would be driven into the ground near the panel as well.

There may also need to be additional modifications made to your main panel inside your house to make room for the additional circuit.