少点错误 2024年08月01日
Recommendation: reports on the search for missing hiker Bill Ewasko
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本文推荐了 Tom Mahood 的博客文章和 Adam “KarmaFrog1” Marsland 的视频,这两者都详细记录了 2010 年 Bill Ewasko 在约书亚树国家公园失踪的案件。Ewasko 在一次徒步旅行中失踪,历经十多年才被发现。作者通过分析搜救过程、地理环境和相关线索,探讨了失踪人员搜救的复杂性以及理性思考在解决问题中的重要性。

🗺️ **失踪案的背景与搜寻过程:** Bill Ewasko 是一位 66 岁的健壮老人,他在 2010 年进行了一次日间徒步旅行,之后便与外界失去联系。搜救行动从一开始就持续进行,但直到 2022 年才在偏远地区发现了他的遗体。作者详细记录了搜救行动的各个阶段,包括搜寻区域的划分、搜寻方法的调整以及搜救人员的思考和决策过程。

📱 **手机信号的线索与分析:** Ewasko 失踪两天后,他的手机信号在一个特定的手机塔附近出现了一次,但位置与他最后可能的位置相差甚远。这一线索为搜寻行动提供了重要参考,但同时也带来了新的谜团。作者分析了手机信号的局限性,以及信号出现的原因和可能的解释。

🧭 **搜救策略与地形挑战:** 约书亚树国家公园的广阔地形和复杂环境为搜救行动带来了巨大的挑战。作者详细描述了搜救策略的制定,包括从最可能的位置开始逐渐扩大搜寻范围,以及如何根据地形特征和气候条件进行调整。

🔍 **理性思考与证据分析:** 作者强调了理性思考在解决问题中的重要性。通过对 Ewasko 失踪案的调查,作者展示了如何基于证据进行推理,如何排除不合理的可能性,以及如何根据新的发现不断调整自己的观点。

🕵️ **多角度的思考与探究:** 作者不仅关注了搜救行动的实际过程,还探讨了搜救过程中涉及的各种因素,包括人类心理、环境因素、搜救技术等。通过多角度的思考,作者试图揭示失踪人员搜救的复杂性,以及在面对未知情况时的理性思考和科学方法的重要性。

🕵️ **理性思考与证据分析:** 作者强调了理性思考在解决问题中的重要性。通过对 Ewasko 失踪案的调查,作者展示了如何基于证据进行推理,如何排除不合理的可能性,以及如何根据新的发现不断调整自己的观点。

🕵️ **多角度的思考与探究:** 作者不仅关注了搜救行动的实际过程,还探讨了搜救过程中涉及的各种因素,包括人类心理、环境因素、搜救技术等。通过多角度的思考,作者试图揭示失踪人员搜救的复杂性,以及在面对未知情况时的理性思考和科学方法的重要性。

🕵️ **理性思考与证据分析:** 作者强调了理性思考在解决问题中的重要性。通过对 Ewasko 失踪案的调查,作者展示了如何基于证据进行推理,如何排除不合理的可能性,以及如何根据新的发现不断调整自己的观点。

🕵️ **多角度的思考与探究:** 作者不仅关注了搜救行动的实际过程,还探讨了搜救过程中涉及的各种因素,包括人类心理、环境因素、搜救技术等。通过多角度的思考,作者试图揭示失踪人员搜救的复杂性,以及在面对未知情况时的理性思考和科学方法的重要性。

🕵️ **理性思考与证据分析:** 作者强调了理性思考在解决问题中的重要性。通过对 Ewasko 失踪案的调查,作者展示了如何基于证据进行推理,如何排除不合理的可能性,以及如何根据新的发现不断调整自己的观点。

🕵️ **多角度的思考与探究:** 作者不仅关注了搜救行动的实际过程,还探讨了搜救过程中涉及的各种因素,包括人类心理、环境因素、搜救技术等。通过多角度的思考,作者试图揭示失踪人员搜救的复杂性,以及在面对未知情况时的理性思考和科学方法的重要性。

Published on July 31, 2024 10:15 PM GMT

Content warning: About an IRL death.

Today’s post isn’t so much an essay as a recommendation for two bodies of work on the same topic: Tom Mahood’s blog posts and Adam “KarmaFrog1” Marsland’s videos on the 2010 disappearance of Bill Ewasko, who went for a day hike in Joshua Tree National Park and dropped out of contact.

2010 – Bill Ewasko goes missing

2022 – Ewasko’s body found

And then if you’re really interested, there’s a little more info that Adam discusses from the coroner’s report:

(I won’t be fully recounting every aspect of the story. But I’ll give you the pitch and go into some aspects I found interesting. Literally everything interesting here is just recounting their work, go check em out.)

Most ways people die in the wilderness are tragic, accidental, and kind of similar. A person in a remote area gets injured or lost, becomes the other one too, and dies of exposure, a clumsy accident, etc. Most people who die in the wilderness have done something stupid to wind up there. Fewer people die who have NOT done anything glaringly stupid, but it still happens, the same way. Ewasko’s case appears to have been one of these. He was a fit 66-year-old who went for a day hike and never made it back. I don’t recommend these because Ewasko’s story was particularly mind-boggling. 

This is also not a triumphant story. Bill Ewasko is dead. Most of these searches were made and reports written months and years after his disappearance. We now know he was alive when Search and Rescue started, but by months out, nobody involved expected to find him alive.

Ewasko was not found alive. In 2022, other hikers finally stumbled onto his remains in a remote area in Joshua Tree National Park; this was, largely, expected to happen eventually.

I recommend these particular stories, when we already know the ending, because they’re stunningly in-depth and well-written fact-driven investigations from two smart technical experts trying to get to the bottom of a very difficult problem. Because of the way things shook out, we get to see this investigation and changes in theories at multiple points: Tom Mahood has been trying to locate Ewasko for years and written various reports after search and search, finding and receiving new evidence, changing his mind, as has Adam, and then we get the main missing piece: finding the body. Adam visits the site and tries to put the pieces together after that.

Mahood and Adam are trying to do something very difficult in a very level-headed fashion. It is tragic but also a case study in inquiry and approaching a question rationally.

(They’re not, like, Rationalist rationalists. One of Mahood’s logs makes note of visiting a couple of coordinates suggested by remote viewers, AKA psychics. But the human mind is vast and full of nuance, and so was the search area, and on literally every other count, I’d love to see you do better.)

Unknowns and the missing persons case

Like I said, nothing mind-boggling happened to Ewasko. But to be clear, by wilderness Search and Rescue standards, Ewasko’s case is interesting for a couple reasons:

First, Ewasko was not expected to be found very far away. He was a 65-year-old on a day hike. But despite an early and continuous search, the body was not found for over a decade.

Second, two days after he failed to make a home-safe call to his partner and was reported missing, a cell tower reported one ping from his cell phone. It wasn’t enough to triangulate his location, but the ping suggested that the phone was on in a radius of approximately 10.6 miles around a specific cell tower. The nearest point of that radius was, however, miles in the opposite direction from the nearest likely trail destination to Ewasko’s car - from where Ewasko ought to be.

The base for a decade of searching. Approximate overlays, info from Mahood and Adam’s work, over Joshua Tree National Park visitor map. 

If you’ve spent much time in wilderness areas in the US, you know that cell coverage is findable but spotty. You’ll often get reception on hills but not in valleys, or suchlike. There’s a margin for error on cell tower pings that depends on location. Also, in this case, Verizon (Ewasko’s carrier) had decent coverage in the area – so it’s kind of surprising, and possibly constrains his route, that his cell phone only would have pinged once.

All of this is very Bayesian: Ewasko’s cellphone was probably turned off for parts of his movement to save battery (especially before he realized he was in danger), maybe there was data that the cell carrier missed, etc, etc. But maybe it suggests certain directions of travel over others. And of course, to have that one signal that did go out, he has to have gotten to somewhere within that radius – again, probably.

How do you look for someone in the wilderness?

Search and rescue – especially if you are looking for something that is no longer actively trying to be found, like a corpse – is very, very arduous. In some ways, Joshua Tree National Park is a pretty convenient location to do search and rescue: there aren’t a lot of trees, the terrain is not insanely steep, you don’t have to deal with river or stream crossings, clues will not be swept away by rain or snow.

But it’s not that simple. The terrain in the area looks like this:

(I haven’t been to Joshua Tree myself, but going from Adam’s videos, this is representative of the kind of terrain. || Photo in Joshua Tree National Park by Shane Burkhardt, under a CC BY-NC 2.0 license.)

There are rocks, low obstacles, different kinds of terrain, hills and lines of sight, and enough shrubbery to hide a body.

A lot of the terrain looks very similar to other parts of the terrain. Also dotted about are washes made of long stretches of smooth sand, so the landscape is littered with features that look exactly like trails.

Also, environmentally, it’s hot and dry as hell, like “landscape will passively kill you”, and there are rattlesnakes and mountain lions.

When a search and rescue effort starts, they start by outlining the kind of area in which they think the person might plausibly be in. Natural features like cliffs can constrain the trails, as can things like roads, on the grounds that if a lost person found a road, they’d wait by the road. 

You also consider how long it’s been and how much water they have. Bill Ewasko was thought to have three bottles of water on him – under harsh and dry circumstances, that water becomes a leash, you can only go so far with what you have. A person on foot in the desert is limited in both time and distance by the amount of water they carry; once that water runs out, their body will drop in the area those parameters conscribe.

Starting from the closest, most likely places and moving out, searchers first hit up the trails and other clear points of interest. But once they leave the trail? Well, when they can, maybe they go out in an area-covering pattern, like this:

Map by Tom Mahood of one of his search expeditions, posted here. The single-dashed line is the cellphone ping radius.

But in practice, that’s not always tenable. Maybe you can really plainly see from one part to another and visually verify there’s nothing there. Maybe this wouldn’t get you enough coverage, if there are obstacles in the way. There are mountains and cliff faces and rocky slopes to contend with. 

Also, it’s pretty hard to cover “all the trails”, since they connect to each other, and someone is really more likely to be near a trail than far away from a trail. Or you might have an idea about how they would have traveled – so do you do more covering-terrain searching, or do you check farther-out trails? In this process, searchers end up making a lot of judgment calls about what to prioritize, way more than you might expect.

You end up taking snaky routes like this:

Map by Tom Mahood, posted here. This is a zoom-in of a pretty small area. Blue was the ground covered in this single expedition, green and red are older search trails, and the long dashed line is the cellphone ping radius.

The initial, official Search and Rescue was called off after about a week, so the efforts Mahood records – most of which he is doing himself, or with some buddies – constitute basically every search that happened. He posts GPS maps too, of that day’s travels overlaid on past travels. You see him work outward, covering hundreds of miles, filling in the blank spots on the map.

Mahood is really good at both being methodical and explaining his reasoning for each expedition he makes, and where he thinks to look. It’s an absolutely fascinating read.

43 expeditions in, in December 2012, Mahood writes this:

In this image, one map square is ~one mile.

 

The purple dot is my addition. This is where Ewasko’s body was found in 2022. Mahood wrote this about the same trip where (as far as I can tell) he came the closest any searcher ever got to finding Ewasko. Despite saying it was the end game, Mahood and associates mounted about 50 more trips. Hindsight is heartbreaking.

Making hindsight useful

Hindsight haunts this story in 2024. It’s hard to learn about something like this and not ask “what could have stopped this from happening?”

I found myself thinking, sort of automatically, “no, Ewasko, turn around here, if you turn around here you can still salvage this,” like I was planning some kind of cross-temporal divine intervention. That line of thinking is, clearly, not especially useful.

Maybe the helpful version of this question, or one of them, is: If I were Ewasko, knowing what Ewasko knew, what kind of heuristics should I have used that would have changed the outcome?

The answer is obviously limited by the fact that we don’t know what Ewasko did. There are some specifics, like that he didn’t tell his contacts very specific hiking plans. But he was also planning on a day hike at an established trailhead in a national park an hour outside of Palm Springs. Once he was up the trail, you’ll have to watch Adam’s video and draw your own conclusions (if Adam is even right.)

Mahood writes: “People seldom act randomly, they do what makes sense to them at the time at the specific location they are at.” 

And Adam says: “Most man-made disasters don’t spring from one bad decision but from a series of small, understandable mistakes that build on one another.”

Another question is: If I were the searchers, knowing what the searchers know, what could I have done differently that would have found the body faster?

Knowing how far away the body was found and the kind of terrain covered, I’m still out on this one.

How deep the search got

Moving parts include:

I imagine that it would be really hard to choose to carry on with something like this. In this investigation, there was really no new concrete evidence between 2010 and 2022. As Mahood goes on, in each investigation, he adds the tracks to his map. Territory fills in – big swathes of trails, each of them. New models emerge, but by and large the only changing detail is just that you’ve checked some places now, and he’s somewhere you haven’t checked. Probably.

A hostile information environment

Another detail that just makes the work more impressive: Mahood is doing all these investigations mostly on his own, without help and with (as he sees it, although it’s my phrasing) dismissal and limited help from Joshua Tree National Park officials. The reason Mahood posted all of this on the internet was, as he describes it, throwing up his hands and trying to crowd-source it, asking for ideas.

Then after that - The internet has a lot of interested helpful people – I first ran into Mahood’s blog months ago via r/RBI (“Reddit Bureau of Investigation”) or /r/UnsolvedMysteries or one of those years ago. I love OSINT, I think Mahood doing what he did was very cool. But also on those sites and also in other places there are also a lot of out-there wackos. (I know, wackos on the internet. Imagine.) In fact there’s a whole conspiracy theory community called Missing 411 about unexplained disappearances in national parks, which attributes them vaguely to sinister and/or supernatural sources. I think that’s all probably full of shit, though I haven’t tried to analyze it.

Anyway, this case attracted a lot of attention among those types. Like: What if Bill Ewasko didn’t want to be found? What if someone wanted to kill him? What if the cellphone ping was left by as an intentional red herring? You run into words like “staged” or “enforced disappearance” or “something spooky” in this line of thought, so say nothing of run-of-the-mill suicide.

Look, we live in a world where people get kidnapped or killed or go to remote places to kill themselves sometimes, the probability is not zero. Also – and I apologize if this sounds patronizing to searchers, I mean it sympathetically – extended fruitless efforts like this seem like they could get maddening, that alternative explanations that all your assumptions are wrong would start looking really promising. Like you’re weaving this whole dubious story about how Ewasko might have gone down the one canyon without cell reception, climbing up and down hills in baking heat while out of water and injured - or there’s this other theory, waving its hands in the corner, going yeah, OR he’s just not in the park at all, dummy! 

Its apparent simplicity is seductive.

Mahood apparently never put much stock in these sort of alternate models of the situation; Adam thought it was seriously likely for a while. I think it’s fair to say that “Ewasko died hiking in the park, in a regular kind of way” was always the strongest theory, but it’s the easiest fucking thing in the world for me to say that in retrospect, right? I wasn’t out there looking.

Maps and territories

Adam presents a theory about Ewasko’s final course of travel. It’s a solid and kind of stunning explanation that relies on deep familiarity with many of the aforementioned moving factors of the situation, and I do want you to watch the video, so go watch his video. (Adam says Mahood disagrees with him about some of the specifics – Mahood at present hasn’t written more after the body was found, but he might at some point, so keep an eye out.)

I’ll just go talk a little about one aspect of the explanation: Adam suspects Ewasko got initially lost because of a discrepancy between the maps at the time and the on-the-ground trail situation. See, multiple trails run out of the trailhead Ewasko parked at and through the area he was lost in, including official park-made trails and older abandoned Jeep trails. 

Example of two trails coming out of the Juniper Flats trailhead where Ewasko’s car was parked. Adam thinks BIll could have taken the jeep trail and not even noticed the foot trail. | Adapted from Google Satellite footage from 2024. I made this image but this exact point was first made by Adam in his video.

Adam believes that partly as a result of the 1994 Desert Protection Act, Joshua Tree National Park was trying to promote the use of their own trails, as an ecosystem conservation method. Ewasko believes that Joshua Tree issued guidance to mapmakers to not mark (or de-prioritize marking) trails like the old Jeep roads, and to prioritize marking their official trails, some of which were faint and not well-indicated with signage.

Adam thinks Ewasko left the parking lot on the Jeep road – which, to be fair, runs mostly parallel to the official trail, and rejoins to it later. But he thinks that Ewasko, when returning, realized there was another parallel trail to the south and wanted to take a different route back, causing him to look for an intersection. However, Ewasko was already on the southern trail, and the unlabeled intersection he saw was to another trail that took him deeper into the wilderness – beginning the terrible spiral.

Think of this in terms of Type I and Type II errors. It’s obvious why putting a non-existent trail on a map could be dangerous: you wouldn’t want someone going to a place where they think there is a trail, because they could get lost trying to find it. It’s less obvious why not marking a trail that does exist could be dangerous, but it may well have been in this case, because it will lead people to make other navigational errors.

Endings

The search efforts did not, per se, “work”. Ewasko’s body was not found because of the search effort, but by backpackers who went off-trail to get a better view of the sunset. His body was on a hill, about seven miles northeast of his car, very close to the cellphone ping radius. He was a mile from a road.

In Adam’s final video, on Ewasko’s coroner’s report, Adam explaining that he doesn’t think he will ever learn anything else about Ewasko’s case. Like, that he could be wrong about what he thinks happened or someone may develop a better understanding of the facts, but there will be no new facts. Or at least, he doubts there will be. There’s just nothing left likely to be found.

There are worse endings, but “we have answered some of our questions but not all of them and I think we’ve learned all we are ever going to learn” has to be one of the saddest.

Like I said, I think the searchers made an incredible, thoughtful effort. Sometimes, you have a very hard problem and you can’t solve it. And you try very hard to figure out where you’re wrong and how and what’s going on and what you do is not good enough.

These reports remind me of the wealth of material available on airplane crashes, the root cause analyses done after the fact. Mostly, when people die in maybe-stupid and sad accidents, their deaths do not get detailed investigations, they do not get incident reviews, they do not get root cause analyses.

But it’s nice that sometimes they do.

If you go out into the wilderness, bring plenty of water. Maybe bring a friend. Carry a GPS unit or even a PLB if you might go into risky territory. Carry the 10 essentials. If you get lost, think really carefully before going even deeper into the wilderness and making yourself harder to find. And tell someone where you’re going.


Crossposted to: eukaryotewritesblog.com | Substack | LessWrong



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