In the ancient days when the shore of the Pacific was young, when the white sierras had only recently been heaved upward and the desert itself was in a formative stage, the ocean reached much farther inland than at the present time. It pushed through many a pass and flooded many a depression in the sands, as its wave-marks upon granite bases and its numerous beaches still bear witness. In those days that portion of the Colorado Desert known as the Salton Basin did not exist. The Gulf of California extended as far north as the San Bernardino Range and as far west as the Pass of San Gorgonio. Its waters stood deep where now lies the road-bed of the Southern Pacific railway, and all the country from Indio almost to the Colorado River was a blue sea. The Bowl was full. No one knew if it had a bottom or imagined that it would ever be emptied of water and given over to the drifting sands.
Sea-beaches on desert.
Harbors and reefs.
No doubt the tenure of the sea in this Salton Basin was of long duration. The sand-dunes still standing along the northern shore—fifty feet high and shining like hills of chalk—were not made in a month; nor was the long shelving beach beneath them—still covered with sea-shells and pebbles and looking as though washed by the waves only yesterday—formed in a day. Both dunes and beach are plainly visible winding across the desert for many miles. The southwestern shore, stretching under a spur of the Coast Range, shows the same formation in its beach-line. The old bays and lagoons that led inland from the sea, the river-beds that brought down the surface waters from the mountains, the inlets and natural harbors are all in place. Some of them are drifted half full of sand, but they have not lost their identity. And out in the sea-bed still stand masses of cellular rock, honeycombed and water-worn (and now for many years wind-worn), showing the places where once rose the reefs of the ancient sea.
Indian remains.
The Cocopas.
These are the only records that tell of the sea’s occupation. The Indians have no tradition about it. Yet when the sea was there the Indian tribes were there also. Along the bases of the San Bernardino and San Jacinto Ranges there are indications of cave-dwelling, rock-built squares that doubtless were fortified camps, heaps of stone that might have been burial-mounds. Everywhere along the ancient shores and beaches you pick up pieces of pottery, broken ollas, stone pestels and mortars, axe-heads, obsidian arrow-heads, flint spear-points, agate beads. There is not the slightest doubt that the shores were inhabited. It was a warm nook, accessible to the mountains and the Pacific; in fact, just the place where tribes would naturally gather. Branches of the Yuma Indians, like the Cocopas, overran all this country when the Padres first crossed the desert; and it was probably their forefathers who lived by the shores of this Upper Gulf. No doubt they were fishermen, traders and fighters, like their modern representatives on Tiburon Island; and no doubt they fished and fought and were happy by the shores of the mountain-locked sea.
The Colorado River.
The delta dam.
But there came a time when there was a disturbance of the existing conditions in the Upper Gulf. Century after century the Colorado River had been carrying down to the sea its burden of sedimental sand and silt. It had been entering the Gulf far down on the eastern side at an acute angle. Gradually its deposits had been building up, banking up; and gradually the river had been pushing them out and across the Gulf in a southwesterly direction. Finally there was formed a delta dam stretching from shore to shore. The tides no longer brought water up and around the bases of the big mountains. Communication with the sea was cut off and what was once the top of the Gulf changed into an inland lake. It now had no water supply from below, it lay under a burning sun, and day by day evaporation carried it away.