[written August 10, 2007]
My family joined our Bay Area friends the Creelmans for a visit to Monumental Creek, once again driving south from Emigrant Gap on Forest Road 19, past the North Fork Campground, past the Onion Valley (lower) Meadow, to Forest Road 45, thence on FR 45-2 to the historic Bradley & Gardner Ditch, or Placer County Canal.
This ditch was made in the 1850s, and delivered water to the hydraulic mines of Dutch Flat and Gold Run, as well as to smaller mining camps such as Lost Camp and Blue Bluffs. Its capacity was around two thousand miners' inches of water, a miners' inch being that amount of water which will pass through a hole one inch square, cut through a two-inch-thick plank, six inches below the water surface, in the course of twenty-four hours. This comes to around sixteen thousand gallons per day.
FR 45-2 forks right from FR 45 a quarter mile above Onion Valley, and soon descends to coincide with the Bradley & Gardner Ditch, just a smidgin above the 4800-foot contour. In about a mile it reaches Monumental Creek, a tributary of the East Fork of the North Fork of the North Fork of the American River. The ditch-road is only a hundred feet above the creek, but the forest is thick enough that one can't really see the creek.
The Monuments form a kind of witches' coven of stone pinnacles, huddled around a series of pools and low waterfalls on Monumental Creek. The principal Monument rises sheer one hundred feet from the water, and has a crown of white, which seems to be a combination of a quartz vein, and down-dripping white stains, which I speculate derive from centuries of nesting eagles.
When the Bradley & Gardner reaches Monumental Creek, one is directly above the Monuments, but they are well hidden behind a screen of trees. We followed the ditch-road on up Monumental Canyon, through a brushy clearcut where not only was the historic mining ditch destroyed for the sake of a few sawlogs, but the road which replaced it was left in poor condition, so one fights Ceanothus and stumbles over boulders to make a passage, and then, the final indignity, the road almost imperceptibly rises above the grade of the ditch, the brush so thick one can't see where the two diverge, so that after a time one must simply leave the road and strike downhill a few yards.
There one finds the rather large ditch blessedly intact, and the berm can be easily followed, through the deep woods, and soon one is much closer to the creek, and soon one can see across the canyon to the very same ditch, so it can make sense, as it did for us, to drop to the creek, hop across on a few boulders, and scramble back up the far side, saving hundreds and hundreds of yards of walking.
For the Bradley & Gardner's almost level grade sends it in and out of Monumental Canyon in a tight hairpin course of almost a mile, on both sides. We followed along the scenic path, often lined with large dry-laid stone walls, until we reached a point directly above the Monuments, again, but from this side of the canyon, one has a fabulous view of the pinnacles and the creek.
We rested and enjoyed the view, and then made a retreat, some of us descending directly to the creek and climbing steeply up the far side of the canyon, others keeping to the ditch. When we formed up into one group again, we had lunch, and then walked out to our cars, and drove to the North Fork Campground, parking along The Ninteteen.
We ambled through the campground and followed the trail leading down the North Fork of the North Fork to the lovely waterfalls and pools that Everybody Knows About. Quite a party of young men and women commanded the area around the falls, swimming, laughing, shouting, clambering up the cliffs to make thirty- and forty-foot leaps into the upper pool, or sunbathing on the polished bedrock between the two deep pools. So we located a little ways downstream, swimming in a lesser pool.
I had hoped we could all go out to Big Valley Bluff, miles past Texas Hill and the last of the pavement on The Nineteen, but our cars were too small and low to the ground, and the road too bouldery and rough. So, we declared the day a success, having visited both Monumental Canyon and the Waterfalls Everybody Knows, and having gone swimming.
From a geological standpoint, the Monuments are a curiosity, the whole area having been repeatedly and heavily glaciated: such thin spires of rock could never withstand the inexorable ice. I envision the inner gorge of Monumental Canyon, around the Monuments themselves, to have been filled with glacial sediments, while the ice flowed by, above; and the thin spires arose in that hidden maelstrom, where a river, roaring in darkness, a powerful river of glacial meltwater comprising a hundred times the current summer flow of the creek, a powerful river, slowly dragged along a one-hundred-feet-deep mass of boulders, cobbles, gravel, sand, even clay.
And above, a thousand feet of ice.
Onion Valley's meadows are all glacial meadows, almost certainly silted-in glacial lakes. They are perched on the tellingly low divide between the North Fork of the North Fork, and its East Fork. In this immediate area the dividing ridge was almost destroyed by the ice. There is scarcely any "ridge" left. During the recessionary stades of the last, "Tioga" glaciation, perhaps 13,000 years ago, the ice paused in its retreat, and left various moraines.
It would appear that the larger North Fork of the North Fork Glacier crossed the dividing ridge, overflowing into the East Fork, again and again, over multiple different glaciations, over hundreds of thousands of years, thus gradually wearing the ridge down. This resembles what we see at the head of Bear Valley, where the South Yuba Glacier overflowed, again and again, into the Bear River Canyon, and gradually lowered the dividing ridge. There is essentially no ridge left at the head of the Bear River.
Here at Onion Valley, however, the overflow was not from one canyon, into the head of another canyon; it was from one canyon, into the middle reaches of another canyon, from the North Fork of the North Fork, into the East Fork. So the dividing ridge, almost erased in one area by the glaciers, reappears a little ways down, rising between the canyons into the eminence named Scott Hill. This eminence seems to be formed from an especially siliceous series of strata, in the Shoo Fly Complex of metasedimentary rocks. Probably these resistant strata are quartzite (metasandstone), with some chert.