Monday, January 30, 2006

Visit to Green Valley

I have written so many times about Green Valley, that I hesitate to repeat myself, in order to develop context for remarks about the geologic history there.

Briefly, then, Green Valley is a wider-than-usual reach of the North Fork canyon, where it crosses, at about a right angle, the weak serpentine of the Melones Fault Zone. To the west, the soaring cliffs and pinnacles of Giant Gap (a different and stronger kind of rock, there) seem to shut off Green Valley from the world at large: how often the storms stall over the high country, while lower in the foothills, the sun has breached the clouds: so brooding showers and storm-wrack hover over Green Valley, while in Giant Gap, the fog glows gold and shafts of light from a westering sun burnish the dark cliffs.

It happens that Pleistocene-age sediments, glacial outwash deposits, are abundant in Green Valley, and were vigorously mined. The sediment load of the North Fork would climb well above the river's ability to transport it, during times of glacial maxima, of which there have been many, even within the last hundred thousand years.


Sediment cores from Owens Lake, at the south end of the Owens Valley, east of the High Sierra, which during glacial maxima, overflowed south through a systems of rivers and lakes, into Death Valley--sediment cores reveal no fewer than sixteen episodes of glacial maxima, within the last 52,000 years.

Yet we only have a name for the last few maxima, from about 25,000 to 10,000 years ago: we call it the Tioga glaciation; and we treat these several maxima as one episode.

Many of the outwash deposits in Green Valley are pre-Tioga, but none have been dated with certainty. Some might be what are called Tahoe I, others, Tahoe II, in age, respectively, about 120,000 and 60,000 years ago. Some might be Sherwin in age, about 750,000 years.

It so happens, too, that many relict channels exist to either side of the present river. Some of these were worked by ground sluicing, others by full-on hydraulic mining, and some could only be reached by tunnels. For in these channels is gold.

Imagine that during a glacial episode, the North Fork's sediment load is so extreme that the canyon fills to a depth of 200 feet above the "natural" river level, with boulders and sand etc. washed down from the North Fork glacier, miles up the canyon.

A flood plain exists within Green Valley, a mile long and half a mile wide. The North Fork meanders back and forth across this plain. At any one time, it follows some particular sinuous course. If we had a time-lapse movie spanning a thousand years, or better yet, a few thousand years, we'd see the course of the river, over the Green Valley glacial outwash floodplain, whip back and forth like a snake.

From study of existing temperate-latitude glaciers we deduce that the North Fork carried much more water, then, than it does today. Yet even those raging flows of glacial meltwater could not strip the sediments out of Green Valley.

However, it is natural to imagine that, while the sediments might have been 200 feet deep over the previous bed of the river, to either side, the bedrock floor of Green Valley would rise, until it intersected the floodplain surface, along the northern and southern edges of the plain.

So towards these edges the sediments were not "200 feet" deep; they were, let's say, less than fifty feet deep.

Under such conditions the raging flood-like flows of meltwater might well transiently mobilize the floodplain sediment, near the river, all the way down to bedrock; and if that mass of boulders and sand moves across that bedrock, it carves a channel.

So, considering that over the long term, the course of the river whips back and forth across the floodplain like a snake, we should expect to find many relict channels in Green Valley.

And we do.

We also find many "strath terraces." These are level or gently-sloping areas of bedrock standing fifty feet or more above the present level of the river. For, consider this subtlety of the snake-like, whipping-back-and-forth, glacial-maximum North Fork: imagine again that the extreme flood-stage-like flows have mobilized the sediment column of boulders, sand, cobbles, mud, whatever, down to bedrock.

If the transient channel of the river on the floodplain, mobilizing these sediments, *is itself moving laterally at the same time*, the sediments do not act to carve a distinct bedrock channel, but instead merely plane off the high spots in the bedrock, which project up into the maelstrom of boulders and sand.

Now suppose that the glaciers melted away, so the sediment load returned to modern levels, and the North Fork has rapidly incised through this Green Valley glacial outwash floodplain, and re-occupied, perhaps, its pre-glacial bedrock channel.

This "rapid" incision has likely taken a thousand years or more. During that time the floodplain has been lowered vertically and has shrunk horizontally. The river continues to whip back and forth across its narrower and narrower width. It is a freak of fate if any portion of the original floodplain surface remains intact. But it does happen. And as the river whips back and forth, it strips the outwash down, and exposes strath terraces as it does so.

In some places these strath terraces are quite easy to see. Elsewhere they remain buried under a thin veneer of outwash sediments.

If one were to try to characterize the shape of the bedrock underlying the often-thin veneer of glacial outwash sediments in Green Valley; that is, if one were to draw an idealized cross-section, cutting the canyon walls, and the North Fork, at right angles, by a vertical plane, striking north-south, one would at first glance see that the canyon is symmetrical about the axis of the river: it is about the same to the north as to the south. At second glance one would notice that, above the line of the glacial outwash floodplain, the bedrock canyon walls are steeper, but below that line, the bedrock is at a relative shallow angle.

Then when we examine this region of the profile--the shallow-angled bedrock beneath the outwash plain--we see that, in detail, there is a succession of sloping or level strath terraces and channels, until, flanking the river to either side, there is a lowest last symmetrical pair of strath terraces, about fifty feet above river level.

These are the most recent, Tioga-age, "recessional" strath terraces, cut, one expects, as the floodplain shrank to a narrow band, just before the North Fork re-occupied its pre-glacial channel.

That the North Fork has indeed re-occupied its own pre-Tioga bedrock channel is evidenced by outcrops of a very peculiar type of conglomerate found in Green Valley, always where the outwash sediments were in direct contact with the serpentine bedrock. Some cementing agent, perhaps magnesium, bound the bouldery mass into an amazingly solid rock. These masses of very young conglomerate are found, sporadically, at river level or sometimes well above river level, from the east end of Green Valley, to the west end. And there is one unequivocally true inference we may draw from the river-level position of these conglomerates, which, incidentally, were often so very rich in gold it was like a raisin pudding, except the "raisins" were nuggets of gold--the one almost idiotically true statement we can make about these mysterious conglomerates, is that the North Fork must have already incised to their level, if not below their level, at the time of their deposition.

They are absolutely typical in composition, these conglomerates, so far as the boulders and rocks which comprise most of their volume: they are boulders of granite, of Shoo Fly Complex metasediments, of the Sailor Canyon Formation and Tuttle Lake Formation and a few other metamorphic rock formations, of the North Fork basin upstream from Green Valley.

And add to these a certain proportion of often angular chunks of serpentine from local sources.

At any rate: the idiotically true inference--we were not there to witness this, first hand, hence we infer--is that the North Fork must have cut into the serpentine bedrock to at least the depth of the conglomerate deposits, before they were deposited.

Else how could they exist?

So if we find them at river level, and see them extending under water in places, we know that at the time they were deposited, the river's bedrock channel must have been at much the same level as it is now.

We can safely dismiss the notion that the conglomerates are brand new. Today and for the last ten thousand years they have been steadily eroded away, not deposited. Everything about them shows that.

No, they are old, but on the other hand, they can't be all *that* old. We know that the North Fork has cut about 2500 feet down in 4 million years. This works out to an average rate of incision of more than six inches per one thousand years. This helps us set an upper bound for the age of the conglomerate; but the issues surrounding this are too complex to go into very much, here.

Nowhere do we see the serpentine bedrock floor of the current channel in Green Valley. It is always masked by bouldery sediments. From conversations with gold dredgers in Green Valley, back in the 1970s, I learned that the actual bedrock floor of the channel is sometimes more than fifty feet below the river's surface.

But let us say that it is in fact "fifty feet" below the water level. So if we were to take the "six inches per thousand years" at face value, and were to ask, 'How long ago was the bedrock floor of the channel, where the water surface is, now?', we would deduce at once that the answer would be, 100,000 years.

My own instinct is that the current bedrock channel of the North Fork, in Green Valley, is much the same as it was in Tahoe II times, 65,000 years ago. Between Tahoe II and Tioga glaciations, a warmer and drier interval allowed the Tahoe II outwash plain to be eroded away, and the North Fork established a course through the serpentine bedrock.

Then along came Tioga glaciation, and the outwash plain built up again. The Tahoe II bedrock channel was just exactly where the floodplain was "200 feet" deep. Hence there the sediment column could *not* be mobilized, all the way to bedrock, despite the high, flood-like flows of meltwater. Hence the deepest sediments, near the serpentine bedrock channel floor and walls, were held fixed for many thousands of years, during which time, some kind of serpentine "tea" permeated these deeply buried sediments, and they became cemented into conglomerate.

Then the Tioga ended, the outwash plain was dissected and largely washed away, and these deeply-buried conglomerates were at last exposed.

They are quite curious and can be found in other canyons crossed by the Melones Fault Zone serpentine, as well. Someone should do their doctoral thesis in sedimentology about these very young, yet very tough, gold-bearing conglomerates. Date them, study them, map them.

I set out rather late today, around one in the afternoon, to see what the North Fork looked like, after the flood even of a month ago. I found that the lack of water bars on the Green Valley Trail had led to some moderate erosion along long reaches of the trail, and that several large Digger Pines had fallen on or near the trail, and need to be cut away.

The 1800-foot contour crosses the North Fork in Green Valley. The uplands nearby run about 4100 to 4400 feet in elevation. At about the 2200-foot contour, Ponderosa Pines begin to dominate the forest, along with Douglas Fir; this change in forest type represents the transition from the serpentine bedrock into the glacial outwash deposits; for serpentine is poisonous to Ponderosa Pines and Black Oaks.

The fork between the East and West trails is met not long after reaching the Outwash Ponderosas. I took the East Trail and dropped past Joe Steiner's grave down to the Hotel Site, where a brief rain shower pattered down, and then followed along east to a large mass of white rock rising beside the river. A deep pool is formed there, and, as with many such pools, a large mass of boulders and sand has formed just downstream, where the current slows.

All these near-river-level gravel bars had been reshaped by the flood event of a month ago. They were objects of almost mathematical perfection. If a boulder has any degree of "flatness" to it, and many of our metamorphic rocks will make fine, flat boulders, the river will leave them shingled, the upstream boulders overlapping the downstream boulders, and the flat surfaces tilted so as to face upstream.

In January 1997 a flood event had scoured all small trees and many large trees from the sides of the channel, and from the gravel bars. It was interesting to watch the gravel bars become populated with willows and alders, over the past nine years. Now they have been partly ripped out again, and those which remain are now leaning downstream, and have had their bark scoured away, and seem ghostly skeletons. Everything is raw and primeval, as it was after the January 1997 event. The shingling of the boulders was quite striking and I wondered whether, in the course of a few months even, if animals and people walking these boulder bars will tip one boulder this way, another that way, and the shingling effect will be softened.

So. I was at White Rocks, just upstream from the Hotel Site. The waters of Moonshine Ravine flared out into a powerful waterfall, bursting from a cliff a few yards away, through a drain tunnel from one of the old mines. Casa Loma Ravine enters the North Fork right at the base of White Rocks.

These rocks are some kind of wild card embedded in the serpentine; they may represent a patch of serpentine which was replaced by siliceous rock, molecule by molecule, after the manner or petrified wood. Various boulders from this outcrop are scattered downstream to a distance of hundreds of yards and more; they are often boulders so large as to be well beyond the present North Fork's ability to move them; yet move they did, while within the matrix of bouldery glacial outwash.

The White Rocks are coarsely granular in texture, mimicking granite, but are composed entirely by light-colored minerals, which I take to be predominantly quartz.

Here and there along the margins of the shingled boulder bars were patches of grey sand. I saw the footprints of deer and bobcats and foxes and one small bear.

I wandered about, examining the imprint of the flood. Moving down the river, I came to an area below the Hotel Site, with its fine and quite massive dry-laid stone wall, made from boulders of glacial outwash perched on the hotel's strath terrace. The wall merely expanded the terrace.

Large springs issue forth all along the edge of the terrace. I know of a certainty that several relict channels exits upslope. These become supercharged with groundwater during major rain events and take weeks and months to drain down, and actually, never do drain down, entirely; there are perennial springs, major perennial springs, near the hotel site, for instance.

Such springs form indications that a buried river channel exists. One sees the same pattern in the Tertiary gravels, high on the divides between the canyons: again and again, if a channel nears the existing ground surface, one will see springs. In fact, there is reason to believe that the miners would drive tunnels into the mountainsides, when they found such springs, because they are so closely linked to the ancient Eocene channels.

The same strategy may have been followed in Green Valley. One of the principal tunnels driven through the serpentine into a relict channel is yards west of the Hotel Site and its springs.

The whole day had been cloudy, but around three in the afternoon, or four, the sky west began to glow, and very briefly something like sunlight entered Green Valley. Then the clouds knitted back together and darkness increased.

I continued west and downstream until a cliff stopped further progress, and climbed a couple hundred feet into the Outwash Ponderosa Forest, here dominated by Douglas Fir. I struck a major (but overgrown) trail through the woods which had often caught my eye in years past, but which I have never followed from end to end. Ignoring it, I made my way north and entered Ginseng Ravine, picked up the high mining ditch, and took the Low West Trail steeply up to the West Trail and the fork I had passed a few hours before.

Climbing above the Outwash Ponderosa Forest, I saw that a large flat-bottomed mass of fog hung over the south canyon rim in Giant Gap, the base being at about the 3900' contour.

Such fog masses are quite common during and right after storms in the North Fork. When they have flat bases, it shows that the air has stratified, and that not much wind can be mixing the atmosphere; for the flat base represents the dew point, the air below being too warm to form fog, but the air above, cold enough.

For any given humidity the dew point is found at a certain temperature, and conversely, for any given temperature, the dew point is reached at a certain humidity.

That is, the dew point represents saturation of the gaseous water in the atmosphere: it is forced to condense into droplets, ergo, fog, clouds, and so on.

This fog bank was of what I call the "lee slope" type.

When a wind passes over a ridge at right angles, it will often create a partial vacuum on the lee side, and air rushes up from below to fill this partial vacuum (like an airplane wing). This "air from below" is warmer, and therefore moister, than the air it is replacing. If conditions are right, fog will form as the warmer air uplifted on the lee slope crosses the dew point.

Here a very weak southerly wind (the "wind aloft") was causing lee-slope uplift in Giant Gap, and much more weakly, in Green Valley. Hence a very respectable fog-mass had formed in Giant Gap, while only a thread of fog at the 3900-foot level showed that lee-slope uplift was happening in Green Valley too.

Both were flat-bottomed, showing strong stratification and weak mixing of the atmosphere.

Only the south canyon rim was affected; the north canyon rim was on the windward slope, and was untouched by fog.

Here is a subtlety: although above the canyon rim a southerly wind was causing the lee-slope uplift and thus the fog, down inside the canyon the flow was from the southwest; one could see the fog moving slowly to the left, to the east, up the canyon. But as it entered Giant Gap Ravine, the lee-slope uplift diminished, and the fog trailed away into a narrow point, and evaporated altogether.

One often sees this in the canyon: a fog bank forming at one end, and disappearing at the other.

Not far from the Giant Gap fog mass is a spot about 500 feet below the canyon rim, on the principal spur ridge descending to the river from Giant Gap Ridge, where the spur ridge levels out briefly. It is almost a pass. It so happens that a branch from the western side of the Melones Fault crosses the ridge at this quasi-pass, and a grove of Kelloggs Black Oak grow in the fault shattered rocks of the pass, where soils have developed to a greater depth and a richer yield.

When conditions are right, an arch of fog drape across the spur ridge, right over the pass, right over the Black Oaks of the Fault Zone, and one can watch it come into being on one side, and evaporate into clear air again on the far side.

It can flow in either direction, this fault-zone fog arch. It spans a couple-few hundred yards. Sometimes it is the only patch of fog in the canyon!

It is caused by the entrainment of up- or down-canyon flow of air; all things being equal, if a spur ridge lies athwart the wind, and has a straight, uniform profile, air should move across it more or less smoothly and at the same speed. There should be the usual lee-side uplift.

But let that ridge be interrupted by a quasi-pass, and suddenly the air is able to move more swiftly, across the pass, than higher or lower on the spur ridge.

This can lead to warmer and therefore moister air rising into the pass-entrained winds from the windward side of the spur ridge. And so--let the temperature and humidity be suitable--a fog arch forms.

As I climbed up the trail, moving more rapidly than normal since I realized that the general gloom was deepening and sunset was near, I watched while the global temperature declined. The result was that the flat bottom of the Giant Gap fog bank lowered; it had been at 3900 feet, now it was 3800, 3700 feet, and suddenly the thin thread over the south canyon rim in Green Valley was a large and continuous mass in its own right; it hooked up with the Giant Gap mass, and with other masses rapidly forming from this same lee-slope function, farther up the canyon; the air was astoundingly stratified, and within minutes I was looking at a flat-bottomed fog bank extending east into Humbug Canyon and beyond, and still lowering!

Looking above me, I saw that the dew point had finally lowered enough for fog to begin to form on the north canyon rim, in isolated small patches.

When I finally reached the top of the trail, I was in the fog, and the last light of the day was dwindling into dark.

Such was another fine day in the North Fork.

Wednesday, January 25, 2006

A New Old Trail

Tuesday morning Ron Gould and I drove into Burnt Flat east of Colfax, and took a tour down the Stevens Trail. It was my first time, since the wildfire of 2004.

The day was sunny and clear, verging upon warm.

The Stevens Trail connected Colfax to Iowa Hill, crossing the North Fork American on a bridge near Secret Ravine. The bridge is long gone, but the Stevens is one of the most popular trails in all Placer County. From the Colfax exit on I-80 one proceeds east on the frontage road, Canyon Way, to the parking area. It is about four miles to the bridge site; and there is an idea at large, I hear, to build some kind of bridge there, again.

One can also walk the Stevens from Iowa Hill, west.

All this part of the North Fork is a Wild & Scenic River.

We aimed to explore an old trail beyond Secret Ravine, on the north canyon wall but low to the river, being about 200 feet above. I know I have this trail on at least one of my old maps, but an external hard disk has gone silent, and I can't find it. The Stevens Trail is the fifty-sixth trail described in the abortive 1953 Placer County Trails Ordinance, and its description mirrors an error in mapmaking itself, an error propagated across more than one map, namely, the mislabeling of Secret Ravine as Robbers Ravine.

I had made a few explorations beyond Secret Ravine in years past, and picked up traces of the old trail, without ever reaching the "good part" so plainly visible from the Stevens Trail on the southern, Iowa Hill side of the river. A maze of game trails on steep terrain had made me scout high and low and every which way, finding only scattered remnants of dry-laid stone walls, at what seemed the right elevation, around 200 feet above the river.

It was interesting to see the effects of the 2004 wildfire. It had burned hot near Robbers Ravine, with its pretty waterfalls, and nearly all the trees had been killed, conifers and live oaks alike. But the root systems of the angiosperms were vigorously stump-sprouting, especially notable in the Bay Laurel, with clumps of a dozen or more sprouts spearing six feet high already.

Crossing Robbers Ravine (one is tempted to ascribe the name to the botched 1881 train robbery at Cape Horn, high on the cliffs directly above, but a check of the diary of Steven Allen Curry, a CPRR surveyor, reveals it already had its name in 1865), we broke out onto the sunny open cliffs, with such fine views down the canyon to Mineral Bar and the Iowa Hill Road.

To my horror, a large house has appeared on a ridge crest above Mineral Bar, a house which, like too many others, at Lovers Leap and Bogus Point and Iron Point and Lime Point and above Ponderosa Way, should never, ever, ever have been built. Sensible societies do not sacrifice the best of their scenic heritage to the whims of a few egomaniacs.

This is just what noted educator David Starr Jordan meant, when he suggested a "hilltop ordinance" was needed in Auburn, to protect the scenery. He made the suggestion around 1904!

But this is Placer County, a name fated to suffer anagramation into the word, "parcel," so that I often bitterly ask myself and The World, during one of my interminable internal private rants, "So, which is it going to be? Placer County, or Parcel County?"

And unfortunately, the answer always is, "Parcel County." Supposedly our Republican Supervisors have such a strong belief in private property, they will sacrifice any trail, any swimming hole, any breathtaking canyon view, to the short-term interests of any individual. The sanctity of these private property rights is such that a kind of religion, based, one expects, upon a foundation of shopping malls and subdivisions, holds our Supervisors in its loving thrall.

Oddly, quite strangely, when I pause to think of the thing, these same Republicans cease crowing about the inviolable sanctity of private property, just about the time one asks how legal title to Placer County lands was obtained from its original inhabitants, the Southern Maidu, and the Washoe.

For no legal title was ever obtained, away back when; a few Euro-Californians with consciences made certain that treaties were negotiated with each tribe, exchanging large reservations for a quit claim to their title on all remaining lands. The Indians duly made their marks, and the generals and bigwigs signed the treaties too, and off to Congress they were sent, in 1852.

It was the last chance to put a decent face upon the theft of California from the Indians.

But when the treaties reached our Senate, in far-away Washington, strange to say--who could have guessed such a thing might happen?--the treaties, with their scratchy little marks and squiggles, made by Chief Weimar and so many others, were placed in a sealed secret archive, not to be unlocked for fifty years.

My friend Jay Shuttleworth, who represents the very best spirit of volunteerism in his long-sustained efforts on behalf of the Stevens Trail, my poor poor friend--how it will hurt, when he sees this new house on the hill. Here is scenery celebrated, admired, gasped over, by every person who ever walked that trail. And now Lord Smith has crowned himself King of the Hill and no person who walks the good old Stevens Trail can walk it, now, without paying a perverse kind of homage to this Lord Smith: you avert your eyes.

It is just like going down the old trail to Green Valley, or walking around in Green Valley: one learns not to raise one's head the wrong way, not to lift one's eyes to Moody Ridge, for the Vulture Houses on Lovers Leap Road will strike one dead in one's tracks.

Well, not quite dead. What is hurt is one's faith in human nature, and one's hope that the best and most beautiful places we love, will remain for our children and their children, to love as well. To be caught in the Medusa glare of the Vulture Houses, as they lord it over the Giant Gap of Thomas Moran, and force themselves upon that quintessential scene of all Placer County scenery, is have one's living hoping trusting heart frozen, into an ugly little rock smelling of ashes.

But this is Parcel County.

Again and again the horrible new house reappeared, as we followed the winding Stevens Trail south and east up the American River Canyon.

We were quite struck by the record the recent flood event left; patches of grey sand twenty feet above normal river level, driftwood stuck on cliffs, willows and alders flailed prostrate and skinned of their bark, under the boiling storm of sand and mud and cobbles and boulders. It was very impressive and I recommend a hike on the Stevens if only for that reason, to see the marks of the rarely high water of a few weeks past.

A few flowers were in early bloom here and there, notably, Houndstongue, with its pretty forget-me-not, blue and white blossoms.

At Secret Ravine, about three miles in from where we left Ron's truck, we found a faint fog hovering over the shadowed creek, and frost on the fresh flood sands. There were some thousands upon thousands of ladybugs clinging to tree trunks and so on, in nearly frozen, motionless masses of shiny red hemispheres.

The 2004 wildfire had not crossed Secret Ravine, at least, here at river level.

Soon enough we were repeating the same old exercise: following various roughly level game trails across steep slopes, alert for signs of lopping, or old rock work, or anything to show the line of the trail. Eventually, in somewhat more than a quarter-mile, I should say, we reached the intact portion of the trail. Suddenly we saw signs of lopping, and guessed our compatriots, Evan Jones and Co., had been at work, by the looks of it, two or three years ago. It was quite easy going on a nearly level line in the full sun with incredible views and all I can say is that it is one of the very nicest trails in the North Fork--yet--yet it is reduced to a ghost of a ghost of a trail for that first quarter-mile east of Secret Ravine.

We fully expected to find and follow the main line of the trail back to Secret, on our return, but such was not at all the case. This trail is very seriously disrupted, over a fairly long distance.

There are indications that this old trail--I shall call it, here, the Meta Secret Trail (for it leads up the canyon, beyond Secret Ravine)--was a mining ditch, originally. It is often very suspiciously level. If true, this may supply the answer as to why the trail is so faint, near Secret Ravine itself: that whole section might have been a wooden flume, thus, no very large bench cut was needed, just a few bits of rock wall here and there to bolster the flume.

Then, let a few wildfires come through, and burn the wooden flumes into oblivion, and one has a somewhat discontinuous trail.

That's the good old Meta Secret Trail.

Across the river one sees the Stevens Trail, with huge stone walls, crossing a mossy cliff. It is quite a lovely view.

Unfortunately another Vulture House came into view, away west in the fire area; clearly the firefighters had made noble and successful efforts to save it, despite its perilous position on the canyon rim. Good for the Vulture Family, bad for the North Fork and the rest of us. As a result of the fire and the firefighting, all screening vegetation was gone, and it is just as though a brand new house had been plopped down on the canyon rim.

I became nauseous thinking about the two Vulture Houses lording it over the North Fork and the Stevens Trail.

Also across the river I observed a large bluff-like mass of glacial outwash, forming a terrace about 100 feet high. The whole face looked fresh and raw and recently eroded, and clearly, the North Fork had chewed at the base of the steep gravel bluff, during the recent flood event. However, I was almost certain that that raw steep face had been left by mining, either ground sluicing or hydraulicing, a century and some ago. It is even possible that the Meta Secret Trail began as the very ditch which served that particular mine; in which case, a flume would have crossed the river.

An old tunnel, possibly dating to the Gold Rush itself, had been exposed by the flood. It was driven into the glacial outwash low down towards the bedrock underneath. Probably many tunnels had been driven into the base of that bluff. They have since collapsed or been buried by cave-ins around their entrances. The coarse gold was found on the bedrock at the bases of such glacial outwash terraces, more commonly known as "bars" or "gravel bars."

But these gravel bars are artifacts of the high flows and high sediment loads of the glacial periods; current flood events do little more than nick the bases of such terraces.

We reached an unnamed ravine, with a pretty stream, crossed, and found an old mining ditch trail on the far side, at a slightly lower level. The Meta Secret continued!

After a time, the Meta Secret dropped down to river level, and we saw sunshine just upstream, and worked our ways up to the place, at a sharp bend on the river. We had lunch and, scouting the area, found some miners' camps with much in the way of garbage strewn around, five-gallon buckets and sleeping bags and tarps and just plain garbage. I grabbed an aluminum frying pan and returned to the river.

Wresting clumps of moss from boulders near the water, I washed them into my frying pan and panned the sediments down to black sand. Swirling, some respectable flakes of gold appeared. So Ron and I washed a few more clumps of moss into the pan and found, I don't know, about fifty or a hundred "colors" of gold, among them, some pieces almost big enough to just reach in and pick up. So, it was a little exciting to see all that gold. Probably at least a dollar's worth!

The winter sun, never high, was clearly lowering, we were over a mile east of Secret Ravine, and had another three miles beyond that, to reach the truck. It was time to go, past time, really, and I ended up forty minutes late, picking up my kids at their school bus stop, in Alta.

On our return we followed a higher line at first, following a faint trail climbing west from some ancient cabin terraces. At times this tiny thread of a trail seemed to disappear, but we held the course and found large cairns of slaty slabs where it crossed a rocky spur, and then other ducks and cairns along the way, and found ourselves back on the main Meta Secret just where it had seemed to drop down to river level, on our way in, a couple hours before. So there is actually a fork, at that point, and a steep climb to the left, as one is going in, will make the safest route on to that sunny bend, where Ron and I found so very much gold.

But this left-hand upper trail is extremely hard to see, from the fork. That is, the fork does not by any means look like a fork. It is just the spot, it seems, where the trail suddenly drops to river level.

This last bit of high trail, and the ancient cabin terraces near Gold Strike Bend, may date to the Gold Rush itself, and likely were also in use later, by the Chinese, in the 1860s.

Such was another nice day in the North Fork. I learned some new lessons, too, about how to avert my eyes properly, while walking the Stevens Trail. With a little practice, I may one day walk the Stevens Trail, and find it as beautiful as I did, way back in 2004.

Perhaps if I cup my hands around my eyes, to reduce my field of view?