BA0TJB.1 



THE MUD VOLCANO. 357 



with steep slopes suggests a volcano, at the bottom of which are blaek- 

 ishgraa slimes, not unlike the mud thrown out from many volcanoes. 

 'Hie con. v all about is strewn with clay pellets, showing that occa- 

 sional ( iosivc action throws out the mad for considerable distances, 

 although in most instances the force is only sufficient to raise the clay 

 to the rim of the caldron. Six miles from the Mud Volcano the hotel 

 is reached, near the outlet of the lake. 



YELLOWSTONE LAKE. 



Yellowstone lake has an altitude of 7,741 feet above sea level, is 

 over 20 miles in length and of very irregular width, reaching 15 miles 



across its broadest expansion. It embraces an area of about 140 

 square miles, and it requires a ride of LOO miles along its shore to 

 complete the circuit, Rhyolites encircle the shores of the lake on all 

 sides. On the opposite, or eastern side, the Absaroka range rises as a 

 rugged mass of mountains, mainly composed of andesitic and basaltic 

 rocks, the greater part of them being agglomerates and breccias. 

 Similar rocks form the Promontory mountains projecting into the lake 

 IV,, in the south. Plat Mountain to the south and west of the Promon- 

 tory is a broad inclined table of rhyolite. Mount Sheridan, which 

 stands out boldly to the southwest, is an extinct volcano from whose 

 summits and sides have poured forth vast accumulations of rhyolitie 

 lavas. Surrounding the lake on all sides and extending back from 

 the shore are broad benches of sand and gravel, the highest of which 

 is distinctly marked at 150 feet above the present Level of the lake. 

 This ancient lake bench may be traced along the dill's in llayden 

 valley. On the beach along the west shore may be seen andesitic 

 boulders from the Absaroka range that have been transported by ice 

 across the lake in large quantities. On the arrival of tourists a small 

 steamer makes a trip around the lake, giving an opportunity for 

 Obtaining line views of the Absaroka range. Mount Sheridan, the 

 islands, and the imposing valley of the Upper Vellowstone. 



YELLOWSTONE LAKE TO YELLOWSTONE FALLS. 



In order to visit the Canyon and Falls of the Yellowstone the route 

 follows down the river and across llayden Valley in a northwest 

 direction over an undulating grassy plain. The first object of special 

 interest to the visitor is ('rater hills, where there is a remarkable 

 grouping Of Steam vents and solfataras. These isolated hills, rising 

 above the valley for 150 to 200 feet, are covered from base to summit 

 with hundreds of steam vents, from which issue acid vapors depositing 

 the most delicate sulphur crystals in innumerable cavities and fissures. 

 Only a slight tlow of water is visible at the surface, but at the base 



