Scores of tunnels have been run into the mountain to get at the gravel of this Pactolian river. Millions of dollars of gold have been extracted from its bed, and millions more await the tunnel, upraise, and drift of the adventurous miner.
Beginning at the top of the mountain and working downward, we find the order of materials as follows: A cap of basalt from sixty to three hundred feet thick, a bed of breccia of varying thickness, two hundred feet of conglomerate andesitic sand (volcanic ash of the miners), a bed of pipe-clay, and then auriferous gravel resting on a bedrock of slate. In tapping the ancient river-bed considerable water is encountered flowing through the gravel. To get rid of this water has been a problem of expense and annoyance to the miner.
To measure the time that has passed since this buried river rolled over golden sands staggers the intellect. It is estimated that from one hundred and fifty thousand to four hundred thousand years must have elapsed.
This curiously formed mountain has been likened to a monolithian serpent. Where the Stanislaus River breaks abruptly through the mountain the eye gazes in wonder from the crest down two thousand feet to a seemingly tiny crowded stream below, rushing madly on its way to the sea.
Many interesting remains of animals have been found in the gravels under this mountain. In running a tunnel under Table Mountain some years ago, the miners came across a large mass of tallow weighing about one hundred and fifty pounds, and in proximity were the bones and tusks of a huge animal. Many bones and tusks of the mammoth and mastodon, not to mention the remains of other animals, have been found in the ancient river-bed. Probably some of these elephantine animals were sporting in the water and dashing it over themselves when the stream of lava, sweeping down, overwhelmed them, trying out the tallow and preserving their skeletons for the wonderment of civilized man.
At one place in the mountain the deep roar of a waterfall is heard. At another, where there is a deep break, is a series of passageways and caves where the outlaw Murietta had his hiding-place. In several places on the top of the mountain, by striking the foot down hard, a hollow, reverberating sound is heard. We give in his own words the account of an explorer's visit to the so-called Boston tunnel which runs beneath Table Mountain:
"Hearing of a celebrated petrified tree in the Boston tunnel, which runs under Table Mountain, I determined if possible to see it and procure some specimens. After considerable inquiry I found a miner who said he knew where the tree was; that the tunnel in which it was located had been abandoned many years ago; that no persons had entered it for years; that rocks were constantly falling, making it exceedingly dangerous to enter, and that very likely it was so clogged up with rocks that no one could get to the tree. When I had expressed my great desire to see this tree, and coaxed him, at length he promised to take me to the tunnel to see its condition, but said he would not promise to guide me into it.
"Having dressed ourselves in overalls and jumpers, with candles and geological hammers in hand we set out for our destination. On approaching the tunnel my guide at once began to throw stones into the bushes on either side of the entrance. When asked why he threw the stones, he replied that about the mouth of old tunnels rattlesnakes are wont to resort to get out of the burning sun.
"Not finding any rattlers, we proceeded down the incline to the mouth of the tunnel. Finding the mouth not obstructed, and lighting our candles, we entered. Sometimes crawling on our hands and knees over fallen rock with scarcely a foot of extra room above our heads, then stooping low, then walking upright, again crawling between huge masses of rock and earth, and crowding between slanting monoliths, we made our way through the mud and water dripping on us from the roof above.
"When part way in, the guide hesitated and declared that we were taking our lives in our hands if we went farther; that the five-ton rock lying in front of our path had very recently fallen from the roof, probably a week before, possibly a day or only an hour before. Pointing to the roof with his candle he said: 'Do you see that piece of rock partly detached and ready to fall at any moment?'