Page:Popular Science Monthly Volume 68.djvu/339

 Rh emptying, or rather opening, into the lower part of the Salton basin. Recently, for the sake of wider service, new intakes from the Colorado have been opened. All went well until some eighteen months since, when the Colorado, flushed with flood, rose suddenly twenty feet or more above its usual tide and forthwith, instead of hurrying its waters southward to the gulf, began to pour them down the old abandoned river channels into the Salton sink. The fall to the gulf is only one hundred and thirty-seven feet, while the fall to the basin is, as we have seen, nearly four hundred and the distance not much greater! So there you are; and no earthquakes, volcanoes or sea-water needed in the least!

The whole situation and topography are interesting in the extreme. The geologist will tell you that all the region hereabouts is slowly rising; that once upon a time the head of the Gulf of California was farther north, away north of Yuma, in fact, and received the Colorado there, perhaps where the United States government is now building the new dam; and more, an arm of the gulf extended away west nearly to where now is Indio; and in those days the mud of the stream was deposited farther and farther out in the sea, forming an estuarine deposit, filling up the sea, while, upon the rising bottom, channels of the river ran carrying the mud farther and farther until finally the part of the sea toward Indio was cut off entirely from what now is called the Gulf. The part of the ocean thus isolated presently dried up and left the Salton basin, a salt desert by reason of the evaporated sea-water; and now again, though filled with the fresh water of the river, the wide-forming lake is salt once more in memory of its old-time history.

The botanist too finds curious confirmation of our story. All about the Salton valley, as near Indio and the Palm springs farther west are curious isolated groves of palms, palms of peculiar sort, the Washingtonia, in fact, now commonly planted in south California cities. But Washingtonia should stand by the sea, as the palms of Florida do, run down the shores of the California Gulf—and so these isolated groves are but the remnant of a tropic flora, once rich no doubt, that all but perished with the drying of the old Salton Sea of which geology tells. The old sea was a fact. Part of this beach is yet to be discovered, as is shown upon our map, and no doubt its course might be traced more widely still; its sands along the old-time eastern shore are still blowing about in dunes.

The waters of the Colorado, if allowed their present course, will no doubt bring back conditions of climate long gone by. Already railroad men declare the air too moist. If so, would the palms again extend their sway along the shores and would tropic verdure once more make the bordering mountains green? Who knows?