Anyone who would like to have these points emphasized to them should look up a couple of books that I read cover to cover and really enjoyed* (for certain definitions of "enjoyed"):
"Off the Wall: Death in Yosemite"
"Over the Edge: Death in the Grand Canyon"
Both are by Michael P. Ghiglieri, along with others more specialized in those parks. They are both just basically "here is every single death (and quite a few disappearances) recorded in the park, and a sometimes brief, sometimes longer write-up about the circumstances of each". They're hefty books, but still, in the 100+ years that these parks have existed, it's a finite number, you know? And they're both VERY readable.
I happened to read them both after visiting Yosemite, but before going to the Grand Canyon; so that when I took a trip to the latter, I made sure to drill into my friends' heads "DO NOT EVER leave one person out of your sight", because the main takeaway from those books is, "And they were never seen again, and their body was never found." One of your hiking companions might sit down on a trailside rock to rest for a little bit and tell you to go on, they'll catch up, it's only a half a mile to the end of the trail... do not fall for this. It won't hurt you to sit or stand with them for a while until they're ready to go again.
But mostly the phrase that I made sure stuck in everyone's head was, "Do you have enough water? No, you don't -- here, take some more." Especially in the desert southwest parks (where we went during summer), but this goes for most parks if you're hiking in warm weather.
Because another salient example was that when we arrived at the North Rim of the Grand Canyon and were walking into the visitor center, there was a big sign on a stand right beside the door, and it said (to paraphrase), "Are you in good enough shape to run a marathon?" It went on to report that, not that long before, a woman who had run the Boston Marathon was visiting the GC and went for a hike with a friend. Like MANY PEOPLE, they underestimated the distances (especially common in the desert parks, where you can see for a long way and you are bad at estimating how far away some of the things you can see actually are), and underestimated how much water to take with them, and underestimated how warm out it really was. They hiked for too long and didn't drink enough, and started to experience heat exhaustion. The marathon runner went into heat stroke sooner, IIRC. She sat down in the shade, while her friend tried to hike out to find help. The friend did make it out and survived. The marathon runner died.
The point being: even if you are young and very in shape and athletic, you can still make some very unwise decisions when you head out on a hike into the wilderness. Most people who visit the parks are NOT nearly that in shape or athletic, and they are often making bad decisions, too. Bright Angel trail is the most well-known trail from the South Rim of the GC down to the river. It's 7.8 miles down. (Another sign we saw frequently in GC: "Down is Optional; Up is Mandatory".) There is a park ranger who is stationed to hang around the first few hundred feet of the trail, where it finally just goes below the rim, and their sole purpose is to stop tourists who are descending the trail wearing flip-flops and carrying one (1) 12 oz. bottle of water.
Another anecdote: on the same trip, at the end, two of us went to Mesa Verde NP in Colorado. When we arrived, there were signs posted on basically every building door with a photo of an older man, who had gone missing only the week before. Obviously, the signs were to alert people to watch for anything unusual that might help find the guy (who by that point was probably no longer alive; and in fact it would turn out, he definitely wasn't).
This was Dave Stehling, who was 51. He was there with his wife and elderly parents. They all stayed around the visitor center, while he decided to go on a short, paved quarter-mile hike to a look-out. (Mesa Verde mostly consists of the mesa top, and most trails to see the cliff dwellings and other sights drop down into the canyons. The park is a maze of deep canyons and steep drops from the mesa.) He did not take water with him, although the temps were 90-100 F that day. His wife described him as a little directionally challenged sometimes; but he was on a very short and clear path near the visitor center. An extremely easy hike. Witnesses placed him as having diverted onto the longer (2.8 mile) Petroglyph trail; either he took a wrong turn, or he decided he wanted to see the petroglyphs. Even that longer trail should only have taken a hour to walk.
He disappeared. Despite a massive search (made difficult by the terrain), his body was not discovered for 6 more years. He was the subject of theories about paranormal activity by David Paulides (the guy behind Missing411, who is the source of a LOT of conspiracy theories about people going missing/dying in the national parks/public lands and the NPS covering it up; most of his theories involve Bigfoot, and/or portals to other dimensions, sometimes both). And yes, Stehling's disappearance seems to defy logic. How could you go missing on a short trail, where there is a very finite area into which you might have fallen, and not be discovered by a huge search and rescue effort?
But I've read enough about this kind of thing by now to have read statements by people who work in SAR. And one of the take-aways is that until you experience it firsthand, it's hard to appreciate how difficult it actually is to locate a person who is lost in the wilderness. There are multiple stories about volunteers who played the role of the victim in SAR training -- who would just go out and lay down in the woods and be still and quiet, while a search team tries to find them. And they consistently report the searchers walking past them within touching distance, but not seeing them. (Usually, that has to do with underbrush, but it's also just a testament to how much a body can blend in with its surroundings even if you would *think* it would not; even if you'd think the clothes or something would stand out.)
Stehling's body was found a little over 4 miles away from where he'd disappeared. It seems like he had fallen, probably sustained injuries, but tried to hike out of the canyon he'd fallen into by following it downwards. (I'm not sure that an autopsy was ever released, which is why I don't know if he sustained injuries or not; but in a fall like that, it does seem very likely.) He might have been unconscious during the height of the searching, hidden in dense, scrubby vegetation. In June, he would have had to hike further to finally hit running water. But in the temperatures they were getting at that time, he almost certainly succumbed to hyperthermia.
All of this is just to emphasize what's said in the posts above and in the replies or other posts. A lot of tourists visit the national parks, and they think the word "park" means that it's a tame, safe environment. So many people express shock at the idea that the environment and landscape can hurt them, even though the NPS does post warnings all over the place. They don't take the idea of hiking seriously, and often don't have the right supplies or equipment. They don't realize that even the shortest, friendliest-looking trail can have hazards. They think a running stream looks inviting and they'll just dip their feet in to cool off, and don't realize how fast the current is running or how slippery the rocks are. One of the shortest, flattest, best-paved trails in Yosemite (from the ring road to Mirror Lake) has a sign right by the road warning people that there may be mountain lions around, and not to allow children to run ahead, or trail behind.
And yeah: BISON. And bears. Just yesterday I opened my weather.com app on my phone and on the front page is a video story about some tourists who dragged two black bear cubs out of a tree so they could pose with them to take photos. (This was NOT in a national or state park, but is still an example of people being idiots about interacting with wildlife.) The cubs got away quickly, and authorities "decided not to press charges because the cubs were released quickly". (They should have pressed charged, ffs.) These people will likely never appreciate how lucky they were that the mother bear did not show up.
You really don't need Bigfoot to explain weird disappearances, or paradoxical undressing (something that regularly happens as hypothermia sets in). You don't need holes between dimensions to explain how someone wasn't found by SAR, but their body was later discovered in an area that had been searched previously.
All you need to know is that in 2023, across all of the properties in the national park system, there were 325.5 million visits; an increase of 13 million over 2022 alone. The total population of the United States is 333.3 million. I wish we had a way to estimate how many of those millions were unprepared for the wilderness, but who took risks they shouldn't have anyway. I'd be willing to bet that number is pretty high.
You can't have *nearly the population of the U.S.* venturing out into the wilderness and not expect some of them to die or go missing. Honestly, the surprisingly thing is that it's as relatively rare an occurrence as it is -- deaths and disappearances in the parks still make national headlines.
