It is the last of the Cascades in active eruption, rises between the northern end of the Sierra Nevada Mountains, of which it is locally but wrongly considered a part, and the Klamath Mountains, a spur of the Cascades. Actually it is the southern terminus of the Cascades.
Though quiet for more than two hundred years, the region long has enjoyed scientific and popular interest because it possesses hot springs, mud volcanoes and other minor volcanic phenomena, and particularly because its cones, which are easily climbed and studied, have remained very nearly perfect. Besides Lassen Peak, whose altitude is 10,437 feet, there are others of large size and great interest close by. Prospect Peak attains the altitude of 9,200 feet; Harkness Peak 9,000 feet; and Cinder Cone, a specimen of unusual beauty, 6,907 feet.
Because it seemed desirable to conserve the best two of these examples of recent volcanism, President Taft in 1906 created the Lassen Peak and the Cinder Cone National Monuments. Doubtless there would have been no change in the status of these reservations had not Lassen Peak broken its long sleep in the spring of 1914 with a series of eruptions covering a period of nineteen months. This centred attention upon the region, and in August, 1916, Congress created the Lassen Volcanic National Park, a reservation of a hundred and twenty-four square miles, which included both national monuments, other notable cones of the neighborhood, and practically all the hot springs and other lesser phenomena. Four months after the creation of the national park Lassen Peak ceased activity with its two hundred and twelfth eruption. It is not expected to resume. For some years, however, scientists will continue to class it as semi-active.
These eruptions, none of which produced any considerable lava flow, are regarded as probably the dying gasps of the volcanic energy of the Cascades. They began in May, 1914, with sharp explosions of steam and smoke from the summit crater. The news aroused wide-spread interest throughout the United States; it was the first volcanic eruption within the national boundaries. During the following summer there were thirty-eight slight similar eruptions, some of which scattered ashes in the neighborhood. The spectacle was one of magnificence because of the heavy columns of smoke. Eruptions increased in frequency with winter, fifty-six occurring during the balance of the year.
About the end of March, 1915, according to Doctor J. S. Diller of the United States Geological Survey, new lava had filled the crater and overflowed the west slope a thousand feet. TOn May 22 following occurred the greatest eruption of the series. A mushroom-shaped cloud of smoke burst four miles upward in air. The spectacle, one of grandeur, was plainly visible even from the Sacramento Valley. “At night,” writes Doctor Diller, “flashes of light from the mountain summit, flying rocket-like bodies and cloud-glows over the crater reflecting the light from incandescent lavas below, were seen by many observers from various points of view, and appear to indicate that much of the material erupted was sufficiently hot to be luminous.”
Another interesting phenomenon was the blast of superheated gas which swept down Lost Creek and Hot Creek Valleys. For ten miles it withered and destroyed every living thing in its path. Large trees were uprooted. Forests were scorched to a cinder. Snow-fields were instantly turned to water and flooded the lower valleys with rushing tides.
Later examination showed that this explosion had opened a new fissure, and that the old and new craters, now joined in one, were filled with a lava lid. Following this, the eruptions steadily declined in violence till their close the following December.
As a national park, though undeveloped and unequipped as yet, Lassen has many charms besides its volcanic phenomena. Its western and southern slopes are thickly forested and possess fine lakes and streams. Several thousand persons, largely motorists, have visited it yearly of late. There are hot springs at Drakesbad, just within the southern border, which have local popularity as baths. The trout-fishing in lake and stream is excellent, and shooting is encouraged in the extensive national forest which surrounds the park, but not in the park itself, which is sanctuary. In spite of the hunting, deer are still found.
The greatest pleasure, however, will be found in exploring the volcanoes, from whose summits views are obtainable of many miles of this tumbled and splendidly forested part of California and of the dry plains of the Great Basin on its east.