OP: Yes, I have seen these waiver and indemnity language at several commercial campgrounds in last year. If had not, wouldn't have started this thread. Seems like not too common yet or folks just haven't noticed the fine print.
No, will not mention their names (actually can think of only two at the moment). Have not tried a search on the web, but presumably might be able to find some published on the web.
On a somewhat humorous side note, have also seen automatic consent to having your photograph/video of you used for commercial purposes by an amusement park--you buy a ticket and enter. Language is broad and doesn't necessarily limit to a flattering portrayal of you for amusement park--could end up advertising laxatives for an "affiliate" of the amusement park.
I'm surprised I haven't seen any postings along the lines of (a) you should have read and understood the fine print, your responsibility (see those postings whenever folks complain about refund policies for reservations, warranties, campground policies, etc.), (b) you signed and agreed, so you should abide by those terms, etc.
Ultimately, these provisions may be things we can't do anything about (all in favor of more Walmart parking) unless federal or state laws abrogate these provisions, or courts toss them out. I believe makes it a more uphill battle to pursue claims.
Also don't like the whole concept of registering and signing a whole bunch of boilerplate, besides the waiver and indemnity.