Csdrhrt

If I have an odyssey van with some minor changes (bed, cabinets, etc.) can I sleep in that in the same way I'd sleep in an RV at National Park Campgrounds (in the USA)?

I.e., I know that many say "you can't sleep in your car". But I assume that means you can't do other than designated RV sites.

I'm going to Accept the answer that has the most "official" citations (links to rules, etc.)

The prohibition on sleeping in a car is to prevent people from parking in the parking lots or pull outs and sleeping there and in effect camping outside of designated camp sites.

If you park at a designated campsite that you pay for, nobody is going to care if you sleep in your car or outside or how your vehicle is set up and frankly its none of their business.

In fact there are small vans that can be rented as RVs for exactly that purpose.

Don't run the engine while sleeping as there is a risk of carbon monoxide poisoning.

The advantage of setting up a van to sleep in is that outside of the National parks there are plenty of places where you can just sleep in the van at pullouts or parking lots if necessary.

If you look at the rules in Yosemite, the only time you would have problems with this is if you had a tent only site and slept in the vehicle in the parking lot. Otherwise you are good to go.

I know you asked about national parks, but I thought I would add my experiences which are at state and city/county parks as well.

Most of the time the rule against sleeping in your car is to protect wildlife. If your sleeping in your car in a designated campsite for "RVs" then there should not be a greater impact by your van then a "streamliner". However, if your sleeping in your car at a parking lot, or, especially in primitive camp sits, the park services could get very upset.

As a general rule of thumb, you can think of your van as an RV and sleep in it just like you normally would an RV. If you are in an area where RVs are not allowed then you can be asked to leave, or in some cases face hefty fines.

One other thing to consider is usage. They will get very angry if you are sleeping in your van to avoid the in/out rules, capacity rules, or wildlife protection rules. For example, sleeping in your Van so that you can stay 16 days (14 at the campsite and 2 at the parking lot) will not go over well. Neither will sleeping in your van at a primitive campsite. They will likely have a problem with you sleeping in your van if you have the engine running all the time or are not properly disposing of waste. But if your at a campsite you reserved, in the time frame you observed, not trying to skirt around rules, and just using the van like an RV you should be fine. There are always exceptions though, so you best bet may be to call ahead and check with the ranger station.