Sunday, June 18, 2006

Sugar Pine Point

Saturday's visit to Sugar Pine Point, with the Redbud Chapter of the CA Native Plant Society, was a success. Something like twenty people showed up at Yuba Gap, raring to go someplace wild (but not too wild) with the "legendary" Russell Towle.

Having much interest in our native plants, it is a treat to go out with so many knowledgeable people. Karen Callahan, John Krogsrud, and others were able to identify about everything we found in bloom, including: three species of violet, a faint purple cloud of tiny Collinsia painting a sunny meadow, various penstemon, Calochortus, Coral Root Orchid, Rattlesnake Orchid, Pyrola, Lewisia kelloggii, and some few others. The bloom is only beginning there, at about 5500'.

Sugar Pine Point is where the ridge dividing Big Valley on the west from Little Granite Creek on the east is truncated by the mammoth canyon of the North Fork American. Here, the canyon runs about 3500 feet deep. The SPP ridge stems from the Yuba-American Divide, and runs south a few miles before being truncated by the North Fork; in fact, it forms a classic example of the "glacially-truncated spur ridge," of geomorphology. To the north it is just west of the Loch Leven Lakes.

For a couple miles it runs along level, south of Pelham Flat, and in this reach of the ridge, all slathered with glacial till and even a few weak moraines, well, beneath the glacial veneer, is the Pink Welded Tuff (rhyolite), in a more or less horizontal stratum maybe fifty feet thick, and here as at the head of Palisade Creek, it withstood the ice rather magnificently.

Usually it is not visible, here, the glacial till covering it. It is Oligocene in age. The USGS's David Harwood described it as "Densely welded pink to lavender rhyolite tuff probably equivalent to the Nine Hills Tuff; contains scattered phenocrysts of clear sanidine and lesser amounts of plagioclase, quartz, and hornblende in fine-grained tuffaceous matrix that contains elongate cavities lined with amorphous silica. Potassium-argon age of the Nine Hill Tuff is 24.3 Ma. Maximum thickness 15 m."

Beneath this Pink Welded Tuff is a less-welded unit of white rhyolite ash. Still less is this visible, being weaker than the Pink Welded Tuff.

Beneath these tuffs are the various upturned formations of Paleozoic metamorphic rock, like the Taylorsville Sequence (of formations), and the (Mesozoic) Middle Jurassic Sailor Canyon Formation. These are well exposed in Big Valley. So there is what is called a "profound unconformity" between the horizontal strata of tuff, above, and the vertical strata of (vastly older) metamorphic rock, below.

I had sort of imagined inflicting a ton of geology on all these plant people, but as it happened, I talked about bears so much it seemed to them, anyway, that bears were my one real subject.

The odd-numbered sections out there have been hammered by logging, and the old trails ruined, the very trails on which people used to go backpacking so few years ago it seems, and one can still read their names on the aspen trunks along the trails, with dates in the 1940s, 1950s, 1960s, 1970s, 1980s, ... and then no more. Bulldozers played briefly on the trails, and they were gone, erased as tho they'd never existed. Very little of the Sugar Pine Point Trail remains intact. Our group made slow going of the descent south on the last bit of this trail, only partly ruined by logging, until at last we crossed into Section 20, public land.

There the trail was intact, and we had easy going.

This one-mile-square Section 20 is now designated the Sugar Pine Point Research Natural Area. It is quite a nice place, with a patch of old-growth Ponderosa Pine forest, and with many huge Sugar Pines, hundreds of years old. One is on south-facing slopes within the North Fork canyon, but all one sees are huge trees in every direction, a wonderland, really, with springs and bear wallows and even a bear den, and a host of thousands of young White Fir clog the forest, threatening to overwhelm the millenia-old balance of fire-adapted species, with one single shade-adapted species.

Bears love it there.

I pointed out their persistent footprints as we followed the ancient trail into the tall trees; bears will step in the same spot time after time, week after week, even year after year, and to varying degrees, then, a set of little hollows develops. It is a subtlety, but easy to learn, and soon everyone was spotting bear trails every which way.

Many a tree there, many a huge old pine five or six feet in diameter, is well-scratched by bears. Mostly, one attributes the scratches to territorial markings; but there are some instances less easily figured, such as the monstrous Sugar Pine down on the Little Slate Ridge, commanding the ultimate view of the North Fork canyon, a pine once broken down in some mighty storm of those long-vanished days when men were men, before the money-grubbing Europeans who styled themselves Americans wreaked all their havoc on the Sierra. It is four feet in diameter and maybe forty or fifty feet tall. Having lost its head, side branches became, oh a century ago or more, giant muscled arms two to three feet thick themselves.

And only, I say, only because the good old bears of Sugar Pine Point like to make the climb of thirty feet to these monster branches, only for that reason, the entire trunk of the mighty pine is scratched every which way.

I've never seen the like. Apparently the bears roost up there and enjoy the view. I sometimes think that it must be during those months when snow covers everything, but a sunny interlude will bring bears outside their dens, and the only way to get comfortably clear of the snow, is to climb this ancient broken pine, and take the sun in its giant boughs.

It was a grand day of wandering the old forest and the raw sun-blasted cliffs and getting scratched by brush and breaking sweats and, fortunately, it was not all talking talking talking but plenty of good quiet walking walking walking.

Another great day on the verge of the great canyon. My only regret is that we were somewhat hurried, and could not linger on the majestic cliffs to watch the shadows grow and deepen as sunset approached; that is how it really should be done. Then one walks slowly up through the woods, in twilight.

On the 7.5 minute Duncan Peak quadrangle, note the pass immediately north of that spot labeled Sugar Pine Point. One can contrive to park there, and the old trail drops away to the east for a few dozen yards before breaking south towards the Sacred Forest.

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