Reading some of your comments and projecting them onto the mindset of the unfortunate hikers has me pursuing another angle. That is; the perception of fear of toxic water, dismissing its life-giving properties, may have doomed this family.
(Not that it’s important but I have property 10 crow miles from this location, have hiked the area for over 50 years but not for decades in (a normal) summertime, preferring the high country @ 10,000’ where it is 25 deg cooler (14C). From Mariposa this is not an easy option these days with reservations required and a long entry to Yosemite and then a 2-hour drive)
What I believe, or at least willing to defend:
The party: Decision-making adults seem responsible and enthusiastic. The baby, and lesser extent, dog are problematic and burdensome.
The route: A planned loop hike, minimum five hours and because of conditions (hot), trail features (river) and additional load (baby, dog) easily 6-7 hours. Yes, it’s doable, (but I ain’t doin it, my dogs would bail before me despite running circles around me all day, a punishing, exposed climb in the hot afternoon sun is the Great Equalizer, carrying a dog is a pain, and I’m not hauling a baby carrier, my handful of years in that getup were very bittersweet, the hiking was bitter. The few people I know who would attempt this lean towards ‘hardcore’. I’ve mentioned it before, however, it’s no surprise they were not spotted on trail for 51 hours (assuming 8 am @ TH verified?). But they are eager despite some underestimations, which is common and anticipated and why hikers carry gear.
Gear: An internal bladder pack with minimal water as disclosed by LE, important as a sample exists for testing. Tremendous leap of faith to assume this is all they were carrying. I would be confident they had appropriate clothing, sun protection, food but…it all comes down to water.
Tellingly, did they have filtration equipment and plan to filter along the way? Or without filtration, a carrying capacity of 8L (16 lbs)? If they do have a filter device, however, they are definitely intending to interact with the river.
The River: My, what a beauty! The Wild and Scenic South Fork of the Merced River. If you have an image by now of a toxic, scum-filled cesspool littered with dead trout, it’s time to rethink the Giver of Life. After descending in the morning heat, a welcome sight. Cool, clear water flowing between its gently-sloping shady banks. Attached to this idyllic setting, however, is a cautionary sign.
The Sign: It was prudent for the FS to post the cautionary sign—just that, cautionary, their lowest advisory—about the blue green algal mats/bloom cyanotoxin thing about a month before. It’s real, nothing new, particularly this time of year during recent brutal summers. I’m avoiding it, thanks for the reminder but I’ll still be able to safely enjoy the river—even if limited to soaking my feet as I enjoy a picnic—and yes dogs serve as a canary in the gold mine with these toxins.
As new residents, was the family aware of the sign or the toxin threat before encountering it and, if not, how may this alert have altered their plans, specifically as it relates to drinking water and future on-the-spot decision making?
The Decision: At the midpoint of their hike (in mileage but a relatively easy 4 miles) and at its redeeming feature, did they take inventory of freshwater (hopefully 4-5L min) and fearful of the toxicity of the river, hurry through that two mile oasis, dragging the 60 lbs of baby/water/gear while nervously eyeing the dog in a desperate attempt to outlast their drinking water and outrace the sun in an upward climb?
The climb: Initially pleasant along a side creek canyon also offering sanctuary, soon it turns toward a forsaken, inhospitable, suffocating pit. Up, upwards above the ridge is the vehicle and the new home. But it’s always further than it looks and it’s getting hotter, distress has arrived. From this point on, it never gets better. Taking a look below, however, in clear view is the glint of the river and it’s border of greenery.
The Prognosis: Heatstroke, most definitely I share the prevailing opinion. Why not retreat to the river, submerge and cool your core? Dehydrated and tapped out? Lap it up. We filter for intestinal parasites, which can be uncomfortable a week after exposure. (OK, OK someone will remind me how ‘poisonous’ it is). Many people carry only a 1L collapsible bottle and simple filter and use their judgment whether to filter from source-source but, again, that ain’t me.
Well, with this prognosis, the ‘how comes?’ ‘why didn’t’? ‘I would’ve’? are meaningless. As the brain and organs begin their slow melt, reason and physicality is greatly and progressively impaired. Or, the exact opposite of an adrenaline rush, produced by the brain in response to injury/trauma providing super-human strength, labor-sharp focus and ability to suppress pain.
Heatstroke ain’t like that, there is no ‘fight or flight’, the only signals the brain is sending is “roll over”. The river would have saved them. 12 days later, if experienced outdoors they could still be camping down there. Before reasoning compromised, did they have an unfounded fear of its offerings? It is never easy to decide to turn back, or bivvy, or solicit help when of sound mind.
Every time I think of the baby I break. Propped up like statues, they probably thought all they needed was to rest, in that hellhole, being consumed by it. So sad.
