Miwok / Yosemite - Historic Tradition of the Upper Tuolumne
There is a lake-like expansion of the Upper Tuolumne some four miles long and from a half mile to a mile wide, directly north of Hatchatchie Valley (erroneously spelled Hetch Hetchy). It appears to have no name among Americans, but the Indians call it 0-wai-a-nuh, which is manifestly a dialectic variation of a-wai'-a, the generic word for "lake." Nat. Screech, a veteran mountaineer and hunter, states that he visited this region in 1850, and at that time there was a valley along the river having the same dimensions that this lake now has. Again, in 1855, he happened to pass that way and discovered that the lake had been formed as it now exists. He was at a loss to account for its origin; but subsequently he acquired the Miwok language as spoken at Little Gap, and while listening to the Indians one day he overheard them casually refer to the formation of this lake in an extraordinary manner. On being questioned they stated that there had been a tremendous cataclysm in that valley, the bottom of it having fallen out apparently, whereby the entire valley was submerged in the waters of the river. As nearly as he could ascertain from their imperfect methods of reckoning time, this occurred in 1851; and in that year, while in the town of Sonora, Screech and many others remembered to have heard a huge explosion in that direction which they then supposed was caused by a local earthquake.
On Drew's Ranch, Middle Fork of the Tuolumne, lives an aged squaw called Dish-i, who was in the valley when this remarkable event occurred. According to her account the earth dropped in beneath their feet, and waters of the river leaped up and came rushing upon them in a vast, roaring flood, almost perpendicular like a wall of rock. At first the Indians were stricken dumb, and motionless with terror, but when they saw the waters coming, they escaped for life, though thirty or forty were overtaken and drowned. Another squaw named Isabel says that the stubs of trees, which are still plainly visible deep down in the pellucid waters, are considered by the old superstitious Indians to be evil spirits, the demons of the place, reaching up their arms, and that they fear them greatly.
As given by Mr. Stephen Powers, 1877.