134 GEOLOGICAL SURVEY OF THE TERRITORIES. 



aggregate height of which is 129 feet. The stream, after passing through 

 a deep, gloomy gorge, makes a leap of about 21 feet and then falls again 

 in three streams a distance of over 50 feet into a beautiful, rounded 

 basin, in which the water is perfectly clear and quiet. From this basin 

 the final leap is taken and the water flows on to the Yellowstone Elver. 



Leaving Cascade Creek our next camp (No. 13) was at Mud Volca- 

 noes near the Yellowstone River, about eight miles below the lake. We 

 spent three days here, waiting for a supply-train to join us from Fort 

 Ellis. During this time I visited a number of the various hot-spring 

 localities in this portion of the valley. The underlying rocks here are 

 Pliocene and Post-pliocene, in horizontal strata, and presenting the same 

 characters that were observed near the Grand Caiion, and probably 

 resting, as those do, upon volcanic rocks. In some places I noticed iron 

 as forming a prominent part of these sedimentary deposits, which, with 

 the obsidian, makes very handsome specimens. The river flows quietly 

 through the valley, the fall per mile, from Yellowstone Lake to the top 

 of the upper fall, being only 8 feet, and almost all of this is in the rapids 

 just above the upper fall. The first springs I visited were on a branch 

 of Alum Creek about five miles northwest of camp. We named the small 

 stream Violet Creek, from the profusion of violets growing upon its 

 banks. 



The first spring we met with was on the right bank of the creek, in a 

 siliceous cone-like mound that rises six feet above the bed of the stream. 

 Its temperature was 120° F, , the air being at 70° F. The bed of the creek 

 was filled with confervoidea, leading us to suspect that there were springs 

 still farther up. After a further ride of about a quarter of a mile we 

 came to quite a large group of hot springs lining both sides of the creek. 

 The first spring I will describe is on the right bank of the creek, in the 

 center of a white mound 20 feet in diameter and rising 10 feet above the 

 bed of the creek. This mound is formed of the deposits from the water, 

 which consist mainly of various carbonates and silica. The orifice of 

 the spring is circular and about three inches in diameter and looks as 

 though it had been artificially punched in the deposit, so mathematically 

 exact is it. The water gives oft' carbonic-acid gas, leaving a deposit of 

 iron. Its temperature was 190° F., the air being 70° F. Spring No. 2 

 is on the opposite side of the creek and has a basin measuring 4 feet by 

 2 feet; the temperature of the water was 160° F., the .air remaining at 

 70° F. No. 3 has a circular basin two feet in diameter, which is lined 

 with an abundant deposit of iron. Carbonic-acid gas bubbles through 

 the water. Its temperature was 158° F. No. 4 is 6 feet deep and 1 

 foot by 3 feet in diameter, and has a temperature of 188° F. The 

 next three springs had temperatures as follows : No. 5, 192° F.; No. 6, 

 194° F.; and No. 7, 188° F.; the air still remaining at 70° F. All these 

 springs have circular orifices of about six inches diameter, and the water 

 proceeding from them flows over a series of small terraces, resembling 

 those of the Gardiner's Eiver springs on a miniature scale. These basins 

 are lined with a gelatinous form of silica, which has a leathery appear- 

 ance and is coated with an iron deposit. The springs are about 10 feet 

 above the level of the creek and all give off carbonic-acid gas. No. 8 

 is very irregular in shape and almost hid in the grass, about 40 feet from 

 the creek. There is a slight bubbling in it and its temperature was 

 178° F. No. 9 is a small spring, 2 feet in diameter and 1 foot deep, 

 lined with confervoidea and having a temperature of 140° F. No. 10 

 is a very pretty spring, about four feet above the creek, and has a beau- 

 tiful scalloped edge, moss-lined on one side. Its temperature was 175° 

 F. The boiling-point at this locality is 198°.3 F. None of the springs 



