Monday, September 17, 2007

A Maze of Gorges

[written September 17, 2007]

Ron Gould and I headed up to Emigrant Gap, then a few miles south on Forest Road 19, to Sailor Point. We parked and set off walking down a gated logging road. We hoped to find a way down the ridge dividing Sailor Ravine from the North Fork of the North Fork American River (NFNFAR); for this particular ridge (call it Sailor Spur) stands like a knife-edge above the many waterfalls in that area, forming a narrow promontory wrapped tightly by the 4000' contour.

We had admired that narrow promontory from a distance. Wild, remote, cliff-bound, it would offer a most intimate view of what we call the Gorge of Many Gorges. It also looked to be well-guarded by brush. We could not be certain that some monstrous brush-field would stop us altogether. One could only try.

Half a mile brought us to the noble old Bradley & Gardner Ditch, or Placer County Canal, which was huge, glorious, intact, and very walkable on the west side of the road, but disappeared into the oceanic brush of a Tahoe National Forest clearcut, on the east. We continued down the road, which became tightly hemmed and overhung by brush, mostly that species of Ceanothus we call Deerbrush. In another quarter-mile or so the road struck sharply east, and we dropped away south into the forest, following the ridge.

Despite our fears we had easy going, and as the ridge-crest narrowed, if brush occupied its summit, we just dropped over onto the northern (shady) side of things, where often as not we found that the local bears had had the same idea, and their ponderous footprints could be seen dotting the leafy forest floor. Canyon Live Oak was quite common, with occasional old Ponderosa pines, and a scattered understory of young Douglas Fir. A mass of manzanita, then, might briefly run us off the ridge crest, but we always returned, and over a long distance, a very well-defined bear trail led us directly down the oak-clad crest.

The ridge plunged a couple hundred feet, and then Ron led us across a low swale in the oak forest. He forged ahead, into the sunlight on the far side. Soon I heard exclamations, shouts, and was pleased to think we had Arrived.

But we had not quite Arrived. We had reached the summit of a little spur ridge flaring south from Sailor Spur; this little South Spur had its own knife-edge crest, which dropped very steeply to the river below. We could hear the hiss and roar of several waterfalls. Across the canyon of the NFNFAR, to the south, was the sister-ridge to Sailor Spur, a spectacular knife-edge of rock; since this ridge, dividing the NFNFAR from the East Fork of that river, is named Scott Hill a little ways above and to the east, let us call this drastic arc of cliffs, this sister-ridge, Scott Spur.

Between Sailor Spur and Scott Spur the NFNFAR drops steeply, waterfall after waterfall, pool after pool, in a torturous series of abrupt curves. In a way, the NFNFAR presents the strange chance of a river entering its own gorge from the side. That is, there is a deep canyon; it is the canyon of the NFNFAR; and at a certain point, several streams enter the canyon, from the north, the east, and the south. They are like the fingers of a hand, radiating from the palm: Fulda Canyon, Sailor Ravine, the NFNFAR, the East Fork, Burnett Canyon, and Wilmont Ravine. To varying degrees, these are all "hanging" valleys, with respect to the main canyon of the NFNFAR. That is, their streams have not succeeded in incising their canyons down to the same level as the main NFNFAR. Hence these tributaries all have steep gradients as they approach the NFNFAR canyon. The odd thing is, when you are down in that gorge of many gorges, the NFNFAR seems not so much the main stem of the stream, but just another tributary, and if anything, one which "hangs" higher than usual; and what with its twisted course, there is no looking up the canyon of the NFNFAR: it immediately curves out of view.

So. All these words are only to say that the NFNFAR plunges, very steeply, along a very twisted course, into its own canyon. Into the Gorge of Many Gorges.

We were poised above this twisted, cliff-bound, waterfall-infested gorge, and had a great prospect of the broader region around it: Sawtooth Ridge, and the main canyon of the NFNFAR, were in full view; we could look all the way down the canyon, past Green Valley, to Giant Gap. Closer at hand, most of the various gorges were in view: Fulda, the East Fork, Burnett Canyon. We could see the forested slopes traversed by the China Trail, near Lost Camp.

Soon our little South Spur enticed us into a scramble, looking for some rocky viewpoint, but, having found such a point, we then could see one of the pools and some small waterfalls. They looked so close!

Yet the cliffs below were so steep! I decided to scout farther down the knife-edge crest, and found a kind of steeply-pitching rock ramp which made for pretty easy going. Soon we were on the river itself.

The pool which had enticed me down the cliffs was deep, black, and almost perfectly rectangular, its long axis at right angles to the river, about fifty feet in length by fifteen feet in width. A waterfall entered the center of one long side of the rectangle, and another waterfall left the center of the opposite long side. Although the sun was warm I was not at all tempted to swim. Something about the crystal clarity of the water ... the black depths of the pool ... and the way in which, even at midday, shadows clung to the cliffs falling from Scott Spur, why, the river itself entered the warmth-robbing cliff shadows just a few yards downstream ... so there was no swimming.

The bedrock is all Shoo Fly Complex metasediments, here mostly meta-sandstone, the strata mostly tipped up vertical. The rectangular pool is cut directly along strike of the sediment beds. These beds are up to a couple of feet thick. There is considerable deformation, too, of these rocks, small synclines and anticlines, for instance, and signs of possible soft-sediment deformation, in which (say) underwater landslides disrupted the sediments before they'd ever hardened into rock. In such cases the sediment "layers," the strata, may be formed from fragments of other strata, other layers. Very considerable soft-sediment deformation is visible elsewhere in the Shoo Fly Complex. At times huge blocks of slate were carried along in these underwater landslides, 400 million years ago, and left embedded, any which way up, within a matrix of, say, sandy sediments.

By "huge" I mean, blocks of slate which may be fifty feet on a side. But I saw no such huge exotic blocks here, on the NFNFAR.

We explored up and down only a few yards from the Rectangular Pool, for sheer cliffs and waterfalls stopped us almost immediately. Then we climbed back to the summit of South Spur. We could see our Ultimate Goal, that last long-jutting Promontory of Sailor Spur, a couple hundred yards away. Approaching, we had some trouble with fallen trees. Quite a population of fire-adapted Knobcone Pine lives, and dies, along the almost level crest of the Promontory. Fallen pines lie around like jackstraws. It thus became a bit of a fight to follow the ridge, but soon we were rewarded by amazing, amazing and spectacular views of pools and waterfalls, of gorge upon gorge, canyon upon canyon. We followed along to the very tip of the Promontory, and enjoyed a good break out there, admiring the view, taking photographs.

Then it only remained to make the slow slog back up the ridge. It was quite a good thing to see the truck, and so very fine, to just sit in the truck. It had been less than five miles, less than two thousand feet of elevation loss/gain, but I for one felt, uh, very very well-exercised.

It was another great day, in the main tributary of the North Fork, the North Fork of the North Fork.