Page:Oregon, End of the Trail.djvu/50



The Vale and Owyhee irrigation projects have brought a considerable acreage into high agricultural productivity; and in other sections, such as the Jordan Valley, there are several smaller irrigation projects. The northern portion has a number of adequate highways and railroads, but in the south there has been little transportation development of any kind. The area has considerable mineral wealth, great herds of sheep and cattle, and some horses. Except in the irrigated sections, the population is very sparse. Ontario and Vale are the principal towns.

Altogether, Oregon has a geography of immense diversity and notable contrast. In what is now Lake County, in December, 1843, John C. Fremont ascended to an altitude of seven thousand feet amid snows and howling winds. Suddenly, from a rim, he looked down three thousand feet upon a lake, warm and smiling and margined with green trees and grass. He and his party on that December day picked their way down the declivity, from winter into summer. He named the two points Winter Rim and Summer Lake.

GEOLOGY AND PALEONTOLOGY

Two distinct bodies of land, washed by the primal sea, were the nuclei from which, at an extremely remote period of time, the present state of Oregon was formed. One of these was in what is now the Bald Mountain region of Baker County and the other in the present Klamath-Siskiyou area of southwestern Oregon. The subsequent geological history of the state is chiefly the story of their extension and topographic variation by elevation of the sea bed, by lava flows, by deposits of volcanic ash, and by erosion.

For millions of years these islands alone stood above the water, but during the Triassic period (one hundred and seventy to one hundred and ninety million years ago) the sea, while it still covered most of the present state, had become shallow around the Blue Mountains. Sedimentary beds of this period are found on the northern flanks of the Wallowa Mountains, and typical exposures are seen along Hurricane Creek, Eagle Creek, and Powder River. Rocks of the Jurassic period (one hundred and ten to one hundred and seventy million years ago) are widespread in both the Blue Mountain and the Klamath regions. Fossils of the flora of this period, found at Nichols in Douglas County, and consisting of conifers, cycads and ferns, point to a tropical climate for the region at that time.

At the close of the Jurassic period, or perhaps a little later, there