Los Angeles is not an RV friendly county, as cost of land and various restrictions make developing a park prohibitive. Therefore, to be close to Disneyland you will have to pay. If you are willing to drive for 30 min to 90 min depending on traffic you can find some decent parks. But by national standards they are still very expensive for what is offered. Out my way you have Castaic RV park, Travel Village RV in Valencia by Magic Mountain and perhaps Acton KOA. All will be about 90 minutes from Disneyland, as little as 45 minutes if your lucky, but don't count on that. For one day at Disney all are OK, if your going to do the Parkhopper thing and visit both parks over two days staying close in does have advantages. Also parking at Disney is $20/car and there is limited RV parking (not to mention horrible LA traffic in an RV). You can walk or shuttle to Disney from the local RV parks. The closest RV park to Disney is about a mile walk (not a straight line because of the highway)and you get very little besides a cleaning parking lot with hookups in a close location.
