Son Greg and I met Ron Gould, Catherine O'Riley, and Cindy the Masseuse Wednesday for a hike through Euchre Gorge, between Green Valley on the west and Euchre Bar on the east. From Euchre Bar, we planned to follow the High Ditch Trail up the North Fork of the North Fork to its end, and then rock-hop up the river to the Lucky 3 Claim, and follow the little road up to the Rawhide Mine gate, where we would leave one vehicle; thence back to the top of the Euchre Bar Trail, our point of beginning.
Ron and Catherine and I had made a concerted effort, over the past year, to trace the lines of two of Green Valley's largest mining ditches, through oceans of brush and poison oak. There is a High Ditch, which begins at a minor ravine at the east end of Green Valley, and runs all the way to The Pyramid, at the very west end of Green Valley; so it is roughly a mile in length. The other "big one" is the Green Valley Blue Gravel Mine (GVBGM) ditch, the line of which is cut into cliffs of gray marble at the east end of Green Valley; this ditch took its water from the south bank of the North Fork itself, well upstream from Euchre Bar, and crossed the river on a high wooden flume about half-way between the Bar and Green Valley. Its terminus is in the center of Green Valley.
The High Ditch is up at about 2050' elevation, the GVBGM at about 1950' elevation, while the North Fork itself is crossed by the 1800-foot contour in the middle of Green Valley. The GVBGM ditch is especially notable because it was the kernel of a plan to divert the waters of the North Fork into a canal, to supply the city of San Francisco, in the 1890s. R.L. Dunn, a mining engineer, was one of the principals, and hired on men to rough in the line of the proposed canal through Giant Gap, even driving two tunnels in the massive blades of cliffs below Lovers Leap. The whole project became known as the Giant Gap Survey. We just call it The Survey, and it makes a discontinuous trail all the way from Green Valley on the east, to Canyon Creek on the west, through Giant Gap itself.
We had explored The Survey time and again, and I named it the High Old Upriver Trail or HOUT, inasmuch as we almost always followed it east and upstream from its hidden intersection with the Canyon Creek Trail. But gradually it became clear that this little ledge hacked from the cliffs, with its strangely level course, was in fact that curious footnote to the history of the North Fork, the Giant Gap Survey.
Thus our explorations of the ditches of Green Valley were really a continuation of our earlier intense and recursive reconnaissance of The Survey, in and around Giant Gap. The Green Valley scouting had led us again and again to the Marble Cliffs, where the GVBGM ditch broke out of the Euchre Gorge into the Valley. And the time had come to dare to follow the deadly and tenuous track across those unforgiving cliffs.
10:30 in the morning, the sun bright, the day waxing hot and then hotter, found us at the top of the Euchre Bar Trail (EBT), and perhaps ten minutes' walk carried us down to near the 3000-foot contour, just before the main trail leaves the Iron Point ridge to switch back and forth through the oak woods down to the Bar. We turned onto the almost invisible Iron Point Trail, which forks away west, and dropped into the east end of Green Valley.
This Iron Point Trail (IPT) is not quite where it appears on the 7.5 minute Dutch Flat quadrangle, but then, neither is the main Euchre Bar Trail, in the switchback section. For quite a few years I didn't believe the IPT even existed, having tried and failed to find it both above and below. It is in middling bad shape and, as one makes the final descent into the gentle slopes of Green Valley, is difficult to follow in places, and splits into two trails.
Someone had tied many pieces of bright orange flagging to bushes and trees all along the Iron Point Trail, which we removed. What I consider to be the main (and older) trail in this last section levels out just exactly where Green Valley's High Ditch took its water from a certain ravine (tho one sees no sign of the ditch, across the ravine in thick forest). From there it is an easy ramble south through open oak woods to the Green Valley Blue Gravel Mine ditch.
We were all feeling the heat. I had been lopping brush all the way down the IPT and was dripping with sweat. However, now we would be following the GVBGM on its almost level line, which was quite a relief. We began to notice the rushing murmur of the North Fork.
The relief did not last long. The rather large ditch bore southeast towards the river, and the terrain became cliffier and cliffier. A certain ravine and spring are met, just where the marble begins, where one drops down slightly, and a short scramble is required to regain the line of the ditch, which suddenly is no more than a tiny ledge on a sheer cliff, and that ledge has annoying gaps and outward slants and narrow places.
Catherine gave me permission to describe her as "petrified." Howsoever, we all crossed the nasty section in good time, found one last patch of shade where the ledge broadened, and took a sustained break.
The crystal clear water of the North Fork was gathered into pools large and deep just below us, well, I should say, almost if not entirely 200 feet below us, and we could look across the length of Green Valley to Lovers Leap, and see, all to well, one of the houses where some cute young couple with their shiny SUVs decided to lord it over the North Fork canyon and all the rest of us. How charming, to have an address on Lovers Leap Road! How clever, to hire a bulldozer and any number of men with chainsaws, to clearcut the forest below their house, so as to see the river itself in Green Valley, and the Sierra crest at the head of the canyon!
Green Valley, where the North Fork canyon attains unusual width, and where thick accumulations of glacial outwash gravels dating to a series of glacial maxima over the past several hundred thousand years, were mined and mined and mined for gold--Green Valley is an artifact of the weak serpentine of the Melones Fault Zone. If one were to ask, what would the North Fork canyon look like, were it to cut a band of unusually weak rock, the answer would be, Green Valley. The serpentine might be, is often glibly considered to be, a portion of ocean-floor basalt, now turned up on edge. The right conditions of metamorphism will transform such iron-rich basalt into serpentine.
And if one were to ask, what would the canyon look like, were it to cut through a band of unusually tough and resistant rock, the answer would be, Giant Gap.
So a rare and great contrast is exhibited, between Green Valley on the east and Giant Gap on the west. Giant Gap is a cliff-bound gorge cut about 2300 feet deep into the massive metavolcanic rocks of the Calaveras Complex (ca. 200 m.y. old). The Melones serpentine is in faulted contact withe the Calaveras on the west, and in faulted contact with the Paleozoic (ca. 400 m.y.) Shoo Fly Complex on the east.
But it is more complicated than that, for a narrow band or zone of Mesozoic metasediments actually separates the serpentine from the Shoo Fly (also metasediments). And the Marble Cliffs are part of these metasediments, being beds of limestone, tilted up 90 degrees to vertical, striking north and south across the river. Lens-like shreds of serpentine are mixed into the Mesozoic metasediments, so that this troubling little zone of rocks just east of the Melones Fault Zone should likely be considered to be a tectonic melange within the multiply-stranded fault zone itself. Whether the melange represents scraps of sediments overlying the original ocean-floor basalt, I cannot say.
Having passed the narrow ledge section, we soon left the steep gray cliffs behind and turned the corner into the gorge proper. This whole section of the GVBGM ditch appears to have been a wooden flume; there is never a hint of a ditch dug down into the steep slopes. It made for a nice trail, tho. Canyon Live Oak, California Bay Laurel, Mock Orange, mostly small Douglas Fir, and Poison Oak were common, and had overwhelmed the ditch-trail in many places, so loppers came into play. We passed Sugarloaf Ravine, with is fine high waterfalls, across the canyon, and sometimes had fine views of deep pools below us in the Gorge.
I had made this same hike once in years past, well, actually, several times, but once I'd followed the ditch-trail all the way through from Euchre Bar to Green Valley, and I had a vague memory of a little "side" trail to the river, at the critical point where the GVBGM had crossed the North Fork on its high flume. I couldn't dredge up the details and began worrying that we would pass this side trail; for it is by no means trivial to make the 150-foot descent to the river from the ditch trail. The slopes are quite steep enough up by the ditch trail, and usually steepen into al-out cliffs closer to the river.
Fortunately Ron scouted ahead and quickly found our crucial side trail, which mirrors the general scheme of things by starting off steep, and then steepening further yet, and then following a steeply-pitching ledge down an outright cliff. It took a while to pick our way down this cliff, and one pair of loppers could not take the strain and attempted suicide, clattering desperately onto the unyielding rocks beside the river; but we retrieved them unharmed, and made a short boulder-hop upstream to a fine long pool, fording the river to a gravel bar veneered by sand, with a fire-ring, some little garbage, and, thankfully, a large patch of shade.
It did not take us long to get into the North Fork at last, and swim up and down the pool. The rocks beside the pool were interesting, vertical layers of metasediments; I could not tell for sure whether they were part of the Mesozoic tectonic melange, or the Shoo Fly, but, my money is on the Mesozoic melange. There was no outright marble, but thin layers of limy sediments were in the mix, sometimes beautifully folded.
This counted as a lunch break. We swam, or waded, gingerly, as the case was, and explored up and down the river. Eventually we had to saddle up and press on. A good boulder-hop led us through a kind of tunnel-gate between two huge boulders, and another sandy camp area was reached. From here a well-defined trail continues upstream to the bridge, briefly climbing to the level of the GVBGM but not holding that level.
We crossed the bridge and climbed a short distance, a few hundred yards at most, to the side trail to yet another ditch, certainly close enough to the level of the GVBGM, across the North Fork to the south, that cannot entirely discount the possibility that this ditch, too, supplied water to the GVBGM.
However, my sense has always been that this "High Ditch" ("high" because it is higher than the much lower ditch-line one sees blasted from the rocks on the north bank of the river, above the Euchre Bar bridge)--this High Ditch was built to supply water to the mines of Euchre Bar itself. But my sense could be wrong.
I must bring this account to an end, somehow.
We followed the High Ditch up the North Fork of the North Fork, past the appalling, garbage-strewn miners' camp, to its terminus, and found a shallow pool for some more swimming and another long break in the shade, before making the boulder-hop upstream to The Sidewalks, large planar masses of unequivocal Shoo Fly rocks flanking the river, leading us quickly to the Lucky 3 Claim.
Here some remarkable dry-laid stone walls bolster terraces, presumably an old house site, in the forest just above the river. Gold-dredging equipment and other junk it scattered around. And here a terribly steep little road climbs to the main Rawhide Road. After another rest, we made the climb, and sweat seemed to almost explode from my face, and drip onto the trail in front of me, as I trudged along.
At least we were in the shade.
We hit the Rawhide Road about a half-mile below the gate, and soon enough, tho it seemed to take forever, we reached Ron's truck, and made the jolting drive back up to Iron Point.
We had made a kind of circumambulation of Green Valley's East Knoll and of Iron Point, a hike with occasional river scrambles of perhaps five miles, on a very hot August day. We did have nice strong breezes for most of the hike, and very little trouble with insects.
It is not easy to make the hike between Euchre Bar and Green Valley, on the ditch trail, the GVBGM trail; in particular, the Marble Cliffs are dangerous, and not just anyone's cup of tea. To follow the river itself would require a fair amount of swimming and one heck of a lot of boulder-hopping. I did that once, years ago.
It was another great day on both the North Fork, and the North Fork of the North Fork.