240 



FORESTRY AND IRRIGATION 



May 



which holds the lake appears to be a com- 

 paratively level table-land, containing ir- 

 regular heights rising from the serrated 

 peaks of the crest of the Cascade Moun- 

 tains. Its outer slopes, with well-marked 

 lava-flows and glaciated canyons, eon- 

 forms in general appearance to that of 

 Mount Shasta, across the border in Cali- 

 fornia, with the exception that Shasta 

 rises through even slopes from a com- 

 paratively low base, while Mazama rises 

 among mountains approximating a 

 height of 8,000 feet. At this height 

 the diameter of Shasta and Mazama are 

 about the same, and it is fair to suppose 

 that above this point the latter peak 

 rose at least as high and probably higher 

 than California's grandest mountain. 

 On a conservative estimate no less than 

 17 cubic miles of material above the 

 present rim of the lake remains to be 

 accounted for. Two theories have been 

 advanced ; one, that the mountain, at 

 some mighty convulsion, literally blew 

 its head off, leaving the hole which the 

 water now fills. This theory is appar- 

 ently borne out by the wide area over 

 which pumice and ashes have been 

 thrown, certainly from this now extinct 

 volcano, and at the time of a great erup- 

 tion. The second theory, and, on the 

 whole, the more tenable one, is that the 

 depression was produced by a subsidence 

 of the top of the mountain. The princi- 

 pal argument against the first theory is 

 that the sides of the lake are not torn 

 to fragments as they certainly would 

 have been had such an explosion taken 

 place, and there are generally not suffi- 

 cient evidences in the surrounding 

 country that such a monstrous cata- 

 clysm could have taken place. The 

 theory that the top of the mountain 

 collapsed is borne out by the fact that 

 some of the lava flows of the rim are 

 bent backward into the depression and 

 are so broken off that it seems probable 

 that the sinking took place while they 

 were yet in a molten state. Subsequent 

 activity built up the volcanic cone of 

 Wizard Island in the great caldera 

 which was left. A contractile cooling 



can not account for the loss of so great 

 a mass of matter, nor has there been 

 found an}' vent below the level of the 

 bottom of the lake, where there has 

 been an escape of volcanic material 

 which would compensate for the mass 

 of the top of the mountain. But the 

 fact that the mountain once existed is 

 sufficiently established by the config- 

 uration of the slopes, although the 

 material which once rose majestically 

 in the air to a height of more than 

 14,000 feet has not been altogether ac- 

 counted for. 



Such, in brief, are the principal facts 

 connected with Crater Lake and its 

 origin. Although difficult of access at 

 present, the shortest route calling for 

 some 80 miles of hard staging after 

 leaving the railroad at Ashland, Oregon, 

 the region is destined some day to be- 

 come a well-known and often-visited 

 ' ' public park or pleasure ground for 

 the people of the United States," ac- 

 cording to the words of the act of May 

 22, 1902, establishing it. The area 

 embraced within the park limits 

 amounts to 249 square miles. Even 

 without the lake it would present a 

 wonderful field, not only for the tourist, 

 pleasure- seeker, or sight-seer, but for 

 the scientist, whether interested in the 

 flora and fauna of the region or the 

 geological or mineralogical aspects. 

 No embargo will be placed on such 

 visitors, and everything will be done 

 for their convenience and comfort. 

 But the Secretary of the Interior, in. 

 connection with the Secretary of War, 

 will prevent all wanton depredation, 

 and game and fish will be rigidly pre- 

 served. Special care will be taken to 

 prevent forest fires, and this should 

 render the region immune from what 

 has lately proved to be the most de- 

 structive scourge of the forests of the 

 Northwest. This latter precaution 

 against wanton depredation of the for- 

 ests will help to preserve a wonderful 

 forest of Sugar Pine, in the midst of a 

 belt of timber which is known the world 

 over. 



