Just got back from my "maiden voyage" with my 5th wheel up to Hope Valley/Carson Pass area of the central Sierras. As an FYI, there is a really nice camping area right off the side of the road, starting about 4 miles up Blue Lakes road on the right hand side. Where the first sign that denotes a "T" on the right side is a road that has some great campsites for anyone with any vehicle smaller than a 24.5 foot 5th wheel. I probably "could" have made it up that road, but it would have been a little dicey. Further up the main Blue Lakes road, at the next "T" sign is about 15 or so really nice campsites on the side of a slow moving creek.
The purpose of this post wasn't only to suggest a good spot, but also to note I discovered some "protocols' noted at this camping area. As it was just off a paved road, it appears that everyone seemed "ok" with closer camping. It was not uncommon to see two vehicles who weren't traveling together, be parked within 40 feet of each other in an open area. One thing I noted was several people "pre-parked" their 5th wheels a little aways from the creek, so they would have something to come to on the weekend, I guess- so I assume if you see a trailer parked not right next to the creek in one of these camping areas, you can just "slide right on in". The camping spacing was quite a bit farther than a normal campground, but it still had a "community" feeling to it. I felt obligated to make sure my dogs didn't bark to upset any neighboring campers.
If you ever find yourself near carson pass, I highly recommend this place. There is one campsite that is more remote than the others and has a spectacular view of the sierra crest, but a woman who we camped next to said that site is REALLY hard to get as it is very popular. This road with the campsites parallels the main blue lakes road for probably a mile or so with several entrances. There are several very clean USFS pit toilets right at the entrance of Blue Lakes road, and I am told that you can get water at the USFS campground that is just a mile up the road from the turn off on to Blue Lakes road. There is zero cell service for probably 10 miles in any direction, so don't even try.