Norris assured them that there is air for 50 miles above the earth, and sometimes a tidal wave of atmosphere reaching as high as 200 miles, though after it gets about 190 degrees below zero, less is known about it. Its density is reduced fully half at 18,000 feet,—half a mile above the highest peaks, like Mt. Whitney, but though the air of high altitudes is more buoyant, the cold none the less reduces the speed of the air cruiser.
While they were eating they discussed their itinerary.
Norris had the large trail maps of both Sierra and Sequoia National Forests. These he laid out and pieced together into one big sheet ten feet long. On these maps were marked out the good camp grounds, and where bears, or deer, quail or grouse, might be found, where supplies were obtainable, or pack and saddle stock, guides and packers, or Forest ranger stations (little cabins flying a flag from their peaks, to make them show up on the map).
There were the “roads passable for wagons,” “trails passable for pack stock,” and “routes passable for foot travel only.” There were areas marked with varying tiny green tufts of grass labeled “meadows where stock grazing is permitted,” and “meadows where it is not permitted,” “meadows fenced for the free use of the traveling public” and “meadows fenced for the use of Forest Rangers only.”
Diminutive green pine trees indicated forest areas particularly interesting, striped red areas signalized National Forest timber sales, cut over or in operation, black triangles denoted Forest Service fire outlook stations, and a drawing that looked like a woodshed showed where Forest Service fire fighting tools had been cached in various out-of-the-way places. “TLP” indicated the free Government telephone boxes, red doughnutty-looking circles meant good mountains to climb, with some indication of the safest routes to the top, areas marked out in red diamonds were labeled as geographically interesting, and those in green as botanically of more than ordinary interest.
A green feathery-looking line meant a canyon, a green triangle a waterfall, a plain green line a stream offering good fishing, and a broken green line a stream stocked with young fish, while an X meant a barrier impassable by fish, though what that meant, not one of them could say.
There were various other marks, such as a hub surrounded by the spokes of a wheel (whatever it was intended for), the key to which explained that from that point a good view was to be obtained.
But what most attracted their attention, all up and down the crest of the Sierra Nevada as it stretched from North, North-West to South, South-East, were the wide green areas “of special scenic interest,” most of which was marked “UNEXPLORED!” in great warning red letters.
It was this part of the map that most fascinated the little camping party. Why should they choose a route that was all cut and dried for them, as it were,—where each day they would know when they started out just about where night would find them and what they would meet with on the way? Who wanted their views labeled anyway? That was all very well, very thoughtful of the Forest Service, for inexperienced campers, who would probably never venture into the unknown. But to Ace, the airman, to Ted, with his experienced wild-craft, and to Pedro the romanticist, no less than to the young Yale man whose thirst for far places had led him into the U. S. Geological Survey, the Mystery of the Unexplored called, with a lure that was not to be denied. Long Lester, they knew, was game for anything,—for had he not prospected through these mountains all his life? There was practically no place the sure-footed burros could not go, and there was no danger they were not secretly and wickedly tingling to encounter.
It was a wild region, as rough and as little known as anything from Hawaii to Alaska,—only different. The John Muir Trail, named for the explorer,—a “way through” rather than a trail,—stretched along the crest of the range, the roughest kind of going, (absolutely a horse-back trip, it was generally pronounced), and from its glacier-capped peaks, from 14,500 foot Mt. Whitney, to the even more difficult though less lofty Lyell, ran the Kings’ River, North, Middle, and canyoned South Forks, the Kern and the Kaweah, the Merced and the San Joaquin,—to name only the largest.