camping policy at national parks

Actually we used to do this routinely at state parks, NF campgrounds and, perhaps, NP campgrounds. (for example Half Moon Bay SB) It made room for more campers and allowed us to camp "close by" our friends. They changed the rules a couple of years ago, now it's one RV per site regardless of how much space their is. Note that some campgrounds do have "multi RV"sites but the are not common.

BTW, the Yukon has a much more enlightened rule; they charge by the number of camping units (RV, Tent, etc) rather than by the campsite. In our trip to Alaska we shared campsites at many BC / Yukon/ Alaska locations.