That is a lot for most people. Obviously the upper bound on what's possible is massively higher, but if you take a mildly fit person off the street and put them through 4k feet & 13 miles w/ a 45 lbs pack, they'll be feeling it. An out-of-shape person would be completely destroyed at that point.

The Hiking Gatekeepers: Stop! Who would cross the Blogpost of Death must answer me these questions three, ere the other side he see.

Don't forget that they were also almost 9,000' above sea level, carrying heavy backpacks (probably at least 25 pounds), and breathing in wildfire smoke. The AQI in Mammoth was in the low 200s on Sunday.

Also, they had 7 days to complete the rest of their hike. I suspect the stats for the hike out weren't too difficult, but the cumulative effects were.

A lot of the 8 to 10 thousand foot climbs around here are multi-day because lugging 60 pounds of gear up 4000 feet through 10 or 12 miles of approach is hard work.

That is objectively a lot.

4k feet of elevation gain is a bunch, and 13 miles is no joke. I mountain bike regularly, and most of my rides average around 1300ft of gain. 4k feet would be a long tiring ride.

We started those miles at sunset, after a full day of hiking, and in thick smoke