106 



GEOLOGICAL SURVEY OF THE TEREITORIES. 



white crust, with a few scattered springs, mostly dead. The first 

 group does not differ materially from those described on the East Fork. 

 The aggregated waters form a little stream, which flows westward into 



a small lake in a 

 grove of pines; 

 thence southwest 

 into the Fire-Hole 

 Eiver. (Fig. 37.) 

 One of the springs 

 we named the 

 Thumx^ing or Thud 

 Geyser, from the 

 dull, suppressed 

 sound which is given 

 off as the water rises 

 and recedes. The 

 orifice has a beauti- 

 fully scalloped rim, 

 with small basins 

 around it, 185^. 

 . There is also a long 

 J fissure -spring, the 

 = opening 40 feet long, 

 B 4 feet wide, and 10 

 ^ feet deep, clear as 

 '^ crystal, 175°. Also 

 I a large basin nearly 

 o circular, 50 feet in 

 1. diameter, with a 

 ^ number of huge 

 > apertures, some of 

 o which throw the wa- 

 z terupoOfeet. From 

 one orifice the water 

 shoots up continu- 

 ally 4 to G feet. All 

 around this geyser- 

 group are several 

 smaller springs con- 

 tinually bubbling. 

 There are also a 

 number of reser- 

 voirs once in an act- 

 ive state. There are 

 large numbers of 

 small geysers, some 

 constautlj' shooting 

 up 2 to 10 feet ; oth- 

 ers in a violent state 

 of ebullition, rising 

 and falling; the lat- 

 ter might be called 

 pulsating springs. 

 There is one beauti- 



•>iH;\t^ilil^g; flit 



ful 



spring, 



with a basin so lar^re 



that it looks like a small lake, 25 bv30 



feet, and one can look from the margin down into its clear depths for over 



