I had not heard of getyourassintonature until I read this article.
So I Googled it and there is quite a bit of information about it.
Apparently the man Aidan Weltner has his own website and was at one time on Instagram until they shut him down without explanation
see here, the Instagram event is at the end of the article.
You will notice that it is on Tumblr. I am aware that some here do not like that site, but I have no reliable experience with them as I don't spend a lot of time perusing websites for pictures. It appears that all the photos I saw were either by the author or submitted to him by others engaging in his getyourassintonature adventure. Yes, most of the photos are of young and healthy people, but that happens to be the group he is targeting. Not all are nubile young ladies, there are a couple of pictures that indicate I would be physically comfortable in the group but probably not chronologically compatible.
If visiting a Tumblr site annoys you he has his own site,
here. Read the page he has by clicking on the label "Check out the attn: article on get your ass into nature" and much of what he says is similar to what we discuss here all the time. It's by a young person focused on and intended for young people. We have mentioned here and I have read on other sites of the trend that young people don't seem to be interested in naturism or nudity in particular.
At least he is addressing the issue of getting young people up and out into nature with the motivation that if they try it with no clothes on it will be a memorable experience.
If it works all the better.
Bob mentioned the photo posted by Aidan Weltner. I didn't remember seeing it in the magazine so I checked and it wasn't included in the article. National Geographic has always had the reputation of showing people in other cultures as they are, even if there are topless women or even nudity. It is curious that they didn't include the getyourassintonature photo of all those young people running across a slope in Yellowstone. A perfectly innocent photo of kids enjoying the freedom of running naked through nature without all the reminders of the cultural baggage. Not a single one of them was shown frontal. Puzzling!
At least it was included in the online article.
Duane