CRATER LAKE, OREGON. 373 



The Mazamas held a meeting in August, 1896, at Crater Lake in con- 

 nection with the Crater Lake clubs of Medford, Ashland, and Klamath 

 Falls, of the same State. Recognizing that the high mountain which 

 once occupied the place of the lake was nameless, they christened it, 

 with appropriate ceremonies. Mount Mazama. The rim of the lake is 

 a remnant of Mount Mazama, but when the name is used in this paper 

 reference is intended more especially to that part which has disappeared. 



The inner slope of the rim, so well in view from Victor Rock, although 

 precipitous, is not a continuous cliff. It is made up of many cliffs, whose 

 horizontal extent is generally much greater than the vertical. The 

 cliffs are in ledges, and sometimes the whole slope from crest to shore 

 is one great cliff", not absolutely vertical, it is true, but yet at so high 

 an angle as to make it far beyond the possibility of climbing. Dutton 

 Cliff" on the southern and Llao Eock on the northern borders of the lake 

 are the greatest cliff's of the rim. Besides cliff's, the other elements of 

 the inner slope are forests and talus, and these make it possible at a few 

 points to approach the lake, not with great ease, but yet, care being 

 taken, with little danger. Southwest of the lake the inner slope, clearly 

 seen from Victor Rock, is pretty well wooded, and from near the end of 

 the road, just east of Victor Rock, a steep trail descends to the water. 

 Where fresh talus slopes prevail there are no trees, and the loose mate- 

 rial maintains the steepest slope possible without sliding. Such slopes 

 are well displayed along the western shore opposite the island and near 

 the northeast corner of the lake under the palisades, illustrated in 

 figure 10. At this point the rim is only 520 feet high, and a long slide, 

 called from its shape the Wineglass, reaches from crest to shore. 



The best views of the rim are obtained from a boat on the lake, which 

 affords an opportunity to examine in detail the position and structure 

 of the cliffs. They are composed wholly of volcanic conglomerate and 

 streams of lava arranged in layers that dip into the rim and away from 

 the lake on all sides. Both forms of volcanic material are well exposed* 

 on the trail descending the inner slope, and, although most of the cliffs 

 are of lava, many are of conglomerate. 



On arriving at the water's edge the observer is struck with the fact 

 that there is no beach. The steep slopes above the surface of the lake 

 continue beneath its waters to great depths. Here and there upon the 

 shore, where a rill descends from a melting snow bank near the crest, a 

 small delta deposit makes a little shallow, turning the deep-blue water 

 to pale green. 



As the boat skirts the western shore and passes toward Llao Rock, 

 the layered structure of the rim is evident. This feature is best illus- 

 trated in figure 4. On the whole, the lava streams predominate, 

 although there is much conglomerate. Of all the flows exposed upon the 

 inner slope, that of Llao Rock is most prominent and interesting. In 

 the middle it is over 1,200 feet thick, and fills an ancient valley down 

 the outer slope of the rim. Upon either side it tapers to a thin edge 



