HA( . UK) THE GEYSER BASINS. 353 



LOWER GEYSER HASIN. 



The Lower Geyser basin is about three miles square and is the 

 largest of the geyser areas. It is roughly rectangular in shape and at 



the junction of Firehole river with Xez Perce creek, the lowest 

 ,, int in the basin, has an altitude of 7,100 feet. The Firehole river 

 coming in from the south runs in a northerly direction across the basin, 

 receiving all the waters brought to the surface by the geysers and hot 

 springs. Several tributaries of the river reach the basin from the 

 plateau, and along these streams are a number of active hot-spring 

 areas. Some of them situated along Sentinel creek and Xez Perce" 

 creek are among the most interesting in the basin. The Queeifs Laun- 

 dry an immense hot spring on Sentinel creek, is well worth a visit. 



The Lower Geyser basin contains innumerable hot springs, steam 

 vents, paint pots, mud pots, and 17 geysers. The largest geyser in the 

 basin and one of the finest in the park is the Great Fountain, situated 

 in the extreme southern end of the basin, about one mile south of the 

 hotel. It is in every way a typical geyser. The brilliant, deep blue 

 pool of water measures over 100 feet in diameter, resting upon a broad 

 circular sinter mound, which stands about three feet above the rhyolite 

 base. The formation of siliceous sinter and the phenomena of geyser 

 action are clearly shown here, while the exquisite beauty of the basin 

 will ever place the geyser in the first rank. A large volume of water 

 is thrown violently into the air to a height of 7.") feet. The eruptive 

 action lasts about 20 minutes. 



The Fountain geyser is situated only 200 or 300 yards from the hotel, 

 and plays fairly regularly three or four times a day. Instead of issuing 

 from a cone or mound, the water is thrown out from a funnel-shaped 

 basin. 



A few steps from t he Fountain are the famous Mammoth Paint Pots, 

 similar to others seen throughout the Park, although on a much larger 

 scale. The clay has a delicate blue color and the consistency of dilute 

 porridge. 



Other geysers of interest are the Surprise, Spray, and White Dome. 



LOWEl! TO UPPER GEYSER 15ASIN. 



The road, after leaving the hotel near the edge of the timber on the 

 east side of the Lower Geyser basin, crosses the broad sinter plain, and, 

 after reaching the Firehole, follows closely the bank of that stream to 

 the extreme eastern end of the I'pper (ieyser basin. 



From the junction of the Firehole and Xez Perce creeks, active and 

 extinct hot springs may be seen all along the river bank or in close 

 proximity to it, steam from lissures frequently rising within a few 

 inches of running water and alongside of cold springs. 

 451 ge 23 



