ITINERARY MAIN LINE FROM MEDFORD SOUTHWARD.
Southeast of Medford the valley narrows, and at Talent low foothills of Cretaceous rocks are close to the railroad. The gravels formerly worked in the placer mines seen along here on the right (southwest) are for the most part of Quaternary age. Some gold, however, has been obtained from a Cretaceous conglomerate whose pebbles were derived directly from the still older rocks on which the conglomerate rests. The best known of these placers are those of the Forty-nine group, near Phoenix, which have yielded not only much gold but also a number of Cretaceous fossils. The older rocks on which the Cretaceous conglomerate rests are possibly Paleozoic. Farther south, in the neighborhood of Ashland, these rocks are succeeded along the railroad by a granular igneous rock (quartz diorite) resembling granite. By looking ahead from a point near Ashland the traveler may see a bold rock, Pilot Knob, in the Siskiyou Mountains (a part of the Klamath Mountains). In early days this knob, which stands more than 6,000 feet above the sea, guided immigrants to the pass to California now utilized by the railroad.
Ashland, which passengers generally remember as the fresh-fruit station, is the center of a great peach country and took the prize for peaches at the Chicago Exposition. Pears also are being increasingly grown in this region. Orchards are being rapidly extended southward and westward over the lower slopes of the mountains facing the morning sun. Behind them rise the forested spurs of the Siskiyou Mountains, culminating in Siskiyou Peak (7,662 feet) and Sterling Peak (7,377 feet), which carry snow as late as July. Near Ashland the crumbling quartz diorite is well exposed, together with sandstones and shales of Cretaceous age. To the northeast rises Grizzly Peak (6,000 feet), a pile of lava flows, under which, as may he seen on the gentle slopes near Bear Creek, are sedimentary rocks that contain some beds of coal and fossil plants, probably of Eocene age. The Eocene plants of the Cascade Range are described below by F. H. Knowlton.1
On leaving Ashland the train begins to climb the Siskiyou Mountains, which form the divide between the Rogue and Klamath river basins. The pass is 2,235 feet above Ashland and the ascent is made by a 3.3 per cent gradethat is, at the rate of 174.2 feet to the mile. This average grade is maintained for nearly 30 miles. Shales, sandstones, and conglomerates of Cretaceous age are exposed along the railroad for more than 10 miles beyond Ashland, except a short distance beyond milepost 442, where some of the underlying older (Paleozoic) rocks appear. The Cretaceous rocks continue beyond the first great curve in the railroad line to a point near milepost 416, where an intrusive mass of granodiorite appears and continues to Siskiyou, the summit station. Beyond the second great curve, at milepost 415, there are good views of the valley left behind and of the Cascade Range.
At Siskiyou station the Pacific Highway, which crosses the summit farther east, near Pilot Knob, is near by on the left. Here on September 29, 1841, the Wilkes exploring party crossed the mountain, which was then the boundary between the United States and Mexico. Pilot Knob was named Emmons Peak by Wilkes, after the officer in charge of the party. At Siskiyou the railroad enters a tunnel 3,108 feet long, which passes about 500 feet below the summit. The rock near by is quartz diorite, and this is succeeded by a darker igneous rock (andesite) through which the tunnel has been driven and which, as will be seen farther south, is erupted through sediments of Cretaceous age. Soon after emerging from the tunnel into the drainage basin of Klamath River the traveler obtains his first view of Mount Shasta, one of the finest and most imposing of the snow-capped peaks of the Pacific coast. At milepost 410 Pilot Knob appears on the left (east).
At Colestin, about a mile beyond the end of the tunnel, a modest hostelry has been built near a good spring of effervescent chalybeate water. With its mountain surroundings, a delightful summer climate, and good hunting, this place is likely to be more frequented as its attractions become known. In the descent from Colestin to Hilt (Cole) and thence to Hornbrook the train passes almost continuous exposures of Cretaceous sedimentary beds cut at many places by intruded igneous rocks. Some at least of these igneous rocks are tilted and faulted as much as the sedimentary rocks and consequently may be older than most of the lavas of the Cascade Range, which, as a rule, lie in nearly horizontal attitudes. Before reaching Cole station, at 403.2 miles from San Francisco, the railroad crosses the line between Oregon and California.
bul/614/sec7b.htm Last Updated: 8-Jan-2007 |