128 REPORT UNITED STATES GEOLOGICAL SURVEY. 



water may at some time liave escaped by way of the gulch leading to the 

 springs of group containing ISTos. 88 to 94. The hills or mounds north 

 and west of this sulphury basin with the late-like ponds are generally 

 white tinged with red, presenting the appearance of a burnt district ; 

 the red color is due to the oxidation of the iron in the deposits. 



Springs Nos. 33 to 38 are at the base of the hill which forms the 

 western boundary of the depression. 



No. 33 is a double spouter, throwing water from 2 to 5 feet into the air. 

 Between this spring and the lakes there are numerous vents, mudholes, 

 and spurting springs. 



No. 34 is a bright-yellow sulphur spring about 4 by 4 feet. Back of 

 it, on the slope of the hill, is a pink steam vent, and below is a bluish, 

 drab triangular turbid spring. 



No. 35 is a spring 15 feet in length, with five centers of ebullition. 

 Near No. 35 are several round turbid pools. 



No. 36 is a dark bluish-gray spring 4 by 3 feet, with dull yellow and 

 red border. There is considerable overflow from this spring. 



No. 37. Yellow Crown jSp7'ing.— This is a lemon-yellow -hued mound 

 spring, with an oak-leaf shaped margin. The mound is 5 feet in diame- 

 ter and about a foot high. The basin is 2 feet deep and sulphur-lined. 

 Bubbles escape gently from the small central- orifice. Between Nos. 36 

 and 37 there are a number of small holes. 



No. 38. Two brown-lined pools, about 2 by 3 feet, surrounded by blu- 

 ish-gray geyserite. 



No. 39 is a large lake-like muddy pool. 



No. 40 is a boiling spring about 10 feet in diameter. In the flat below 

 it are a number of vents. 



No. 41 is a dark-gray, almost black, boiling spring, 13 or 14 by 18 feet, 

 with a black and gray border. Between Nos. 40 and 41 there are several 

 springs at the head of a small gulch, and on the hill back of these 

 springs there are steam vents in the timber. 



The group to be described next contains all the principal geysers of 

 the "Gibbon Basin" here described, and is the one first entered when 

 we follow the road coming from the south. After passing by springs 

 Nos. 67 and 71 the road descends into a broad flat, which it crosses and 

 leaves again near the minute geyser, where it begins the ascent of the 

 hill on which springs Nos. 1 to 5 are located. The springs are found 

 mainly to the right or east of the wagon-road and are somewhat con- 

 cealed by trees. There are three gulches leading into the flat, and in 

 these are found a number of important springs. The one that attracted 

 notice first, in 1878, was the great steaming vent on the side of the hill 

 opposite the point where the road enters the basin. A huge column of 

 steam ascends from this with a great roar. This is located on the map 

 as No. 43, Steamboat tent. It consisted of two roaring steam-holes on 

 the side of the hill, that look as though they had just burst through the 

 surface, and the gully leading towards the ravine to the south is covered 

 with sand that appears to have been poured out during an eruption. 

 Trees standing in the line of this sand flood are dead, and a number up- 

 rooted and covered with sand, and some of the trees back of the vents 

 have had their foliage killed, but it had not yet fallen from them. 

 Everything seems to point to the fact of the recent formation of this 

 vent. There is no deposit marking the opening, although stones sur- 

 rounding the hole are beginning to have points of geyserite deposited 

 on their upper surfaces. Whether it is now a geyser with regular 

 periodical eruptions I cannot determine, but that water has been poured 

 from it admits of no doubt, as the gully leading from it presents all 



