170 EEPORT UNITED STATES GEOLOGICAL SUEVEY. 



DESCRIPTION. 



Springs Nos. 1 to 61 form a subgroup on the east side of the river, 

 extending north from the mouth of Fountain Creek. Nos. 5 to 35 and 

 No. 59 are on the top of the bank, or mound, and are divided into three 

 ckisters. The remainder of the springs in the subgroup are on the slope 

 of the mound nearer the river. There are only two springs here that 

 merit description, and these are the Fortress and No. 58. 



No. 4. Fortress Geyser, or Conch Spring. (Plate XII). — This is sup- 

 posed to be a geyser, from the fact that it has built up a mound, or cone, 

 although it has never been seen in action. It is near the river, at the 

 lower end of the sloping bank, and is about 18 feet in diameter. It is 2 

 feet high at the back and four feet in front, on account of the slope in 

 the bank. This crater is about a foot in thickness, and beautifully 

 beaded with pink and gray geyserite. Its sides are broken with open- 

 ings something like port-holes, whence the name. The water boils fu- 

 riously, so that the mass is thrown up 4 to 5 feet above the crater. 

 The overflow is carried off through a channel in a raised water-way, 

 which is two feet in height. This channel is about G inches in width and 

 a couple of inches in depth. The water has a temperature of 201° F. 

 There are periods of activity which are followed by a cessation of the 

 boiling, when the water falls in the crater and there is no overflow. 



No. 58 is below the Fortress, and is a large basin in the laminated 

 masses of deposits which extend in tables over a portion of the spring. 

 It is filled with greenish-tinted water, in which the temperature is 188° 

 F. Back of it is a small bowl, or cone, 2 feet in height, with a flat top, in 

 which the temperature is 164° F., and back of this is another part of the 

 spring (ft), in which the temperature is 190° F. 



Springs Nos. 62-65 form a sort of cluster on the line of the drainage 

 from cluster 31-35, but nearer the river the area in which they are sit- 

 uated is marshy, and beyond them we have a large cluster of springs 

 at the foot of the low bluff. Here only a few temperatures were taken 

 (Nos. 66-85) compared to the number of the springs. I shall mention 

 only two of the group, as they are mainly small and unimportant. 



No. 83. Horn Spring. — This is one of several cones near the river. 

 It is 4^ feet high and 6 inches in diameter at the top, with a much 

 broader base. The temperature was 196° F. The water is in constant 

 ebullition. 



No. 85. Cone Spring. — This is a large cone rising about 10 feet from 

 the edge of the river. It is 4 feet in diameter on top, with an orifice 

 only 2 inches in diameter. The temi^erature was 172° F. There is be- 

 sides this a horn-shaped mass of deposit on the edge of the river. 



Following down the river from the cones we find several springs on a 

 high mound. 



No. 86 is near the edge of the mound and is a white, cavern- like spring, 

 with a temperature of 186° F. 



No. 87 is the main spring on the summit of the mound, and is a cavern- 

 like basin 22 feet long and 15 feet wide, with milky, blue-tinted water, 

 with a temperature of 161° F. The mound breaks oft' abruptly beyond 

 these springs; and just across a ravine filled with muddy pools and steam 

 vents we find the next spring, which is — 



No. 88. Bath Spring. — This handsome boiling spring is at the level of 

 the river, from which it is separated only by a narrow run of hard, cor- 

 rugated geyserite. It has a rather square-shaped basin about 40 feet 

 across. It was named Bath Spring in 1871, although the water is not 



