Rule110 wrote:However, there's a big span between feeling a little out of breath during continued exertion, and being at risk of altitude sickness (which begins at about 10,000 feet for out-of-shape tourists but very few healthy young adults will experience it at that altitude). Professional athletes competing in Denver often take measures (such as traveling to the city early to adjust) to compensate in their training because the city's altitude can noticeably affect their performance. A business traveler from a coastal city to Denver would likely not notice this, unless she has to run after a bus or something. Someone who is doing moderately strenuous exercise but who's in very good shape to begin with might not notice either. It's one of many factors that can affect how out of breath someone feels.
True enough, although acclimation to the altitude is considerably more important than conditioning - at least once acute mountain sickness comes into the picture. Conditioning doesn't help in avoiding AMS symptoms; only acclimation (or to a lesser extent, drugs such as acetazolamide) does.
Rule110 wrote:Higher up, the effect becomes more readily noticeable (but still well below altitude sickness altitudes), such that a hiker even on only slightly sloping or moderately rugged terrain, who has arrived at that altitude over several days giving some time to adjust, would still feel the difference. That seems to be Megan and Cueball's situation. Charlie_grumbles and I both made off-the-cuff handwave estimates of how high Megan and Cueball are based on comparing what they say and what we see with personal experience (and perhaps with charlie's knowledge of mountain cycling). I said about 8000 ft. and he said somewhat over 9000 ft.; those estimates are certainly within one another's error bars.
I'll enter a third voice confirming. I did some hiking in the West in my younger days , although now I live in country where we don't do
high altitude - treeline is about 4200-4500 feet around here). If not acclimated, I'd be hurting
at 8500 feet, and even with acclimation, I'd feel the elevation. Much lower, and I wouldn't notice. I certainly don't notice it on 4500 foot peaks around here. One of the biggest hiking mistakes I ever made was going to 12,500 once, when acclimated to Phoenix. From that time, I can tell you what acute mountain sickness is like.
Rule110 wrote:However, my overall impression has been of a smaller mountain than that, even assuming as I do that we're only seeing vignettes of their travel rather than a continuous panorama. The overall steepness of the slopes (not very steep at all), the vegetation changes and temperature changes (noticeable but not very dramatic despite apparently being at a temperate latitude), the general lack of cliffs, scree, boulders, long slopes at 70% grade or more, steep shoulders (say, 300 consecutive feet of 100%+ grade), or other major obstacles suggests a smaller mountain, or if it's big, one that sprawls very wide. It doesn't seem like the Rockies, for instance.
Unless they've been following a trail! I've been on trails in the West that went quite high, but were graded for livestock right up to the treeline and above. They'd skirt along edging up the talus gradually, and would get really steep only once they hit the headwalls below the high passes. You could take a mule a considerable distance up. (And those last climbs might well call for crampons and ice axe even at high summer.)
Rule110 wrote:Mountains of 8000 or 9000 feet only a few days' walk from sea level should be notable, even if it's not the usual sea level. Unless it's a dramatically lower sea level, but that would be hard to explain while still having tropical climate at 40 degrees latitude.
Hmm. Again. the Pacific coast comes to mind. Is a 300 foot rise in the sea level plausible? That would flood the San Joaquin valley at least as far as Modesto, and Yosemite would be about the right distance from there.
All the rivers run into the sea, yet the sea is not full.
Unto the place from whence the rivers come, thither they return again.