COMPLETION OF THE SURVEY — TRIANGULATION. 211 



The island where we descended is a ridge composed of a stratum 

 of white siliceous sandstone, two hundred feet thick, underlying 

 one of black and gray limestone, which latter constituted its sum- 

 mit, and was filled with fossils of Oystiphyllnm^ Syringipora^ Favo- 

 sites, Fenestella, Streptilasma, and crinoidal joints^ lima in crystal- 

 line limestone, and cyathophyllce. In our return from the top of 

 the mountain, we followed the narrow, dry bed of a ravine or 

 canon that had been formed by the rush of a torrent of melting 

 snows in the spring of the year. It was amazing to see what huge 

 masses of rock had been moved by this agency — many of several 

 tons weight having been carried far into the plain below. As we 

 descended, the gorge, which had at first been almost shut up be- 

 tween perpendicular cliffs of white sandstone, opened out into a 

 superb, wide, and gently sloping valley, sheltered on each side by 

 beetling cliffs to the very water's edge, effectually protected from 

 all winds, except on the east, and covered Avith a most luxuriant 

 growth of rich and nutritious bunch-grass. 



Near the shore of the lake, abundant springs of pure, soft water 

 gush forth, amply sufficient for the consumption of all the stock 

 the valley could supply with food. As a range for cattle, it was 

 all that could be desired ; and is superior to either Tuilla Valley 

 or Antelope Island, on account of the complete protection it affords 

 from the storms of winter, here both long and severe. 



To-day has been one of severe suffering, from the insufficient 

 supply of water we were able to carry with us, every drop of which 

 was consumed long before we commenced our descent from the 

 mountain. 



Thursday^ June 27. — The survey of the laJce was finished yes- 

 terday, having occupied the incessant labour of nearly three 

 months. Nothing now remained but to complete the observations 

 upon the different triangulation stations that had been erected in 

 the course of the examination. The camp was broken up, and we 

 returned to our depot on Antelope Island ; discharged such of the 

 hands as were no longer required, procured a fresh supply of pro- 

 visions from the city, and, on Wednesday, July M, started on our 

 tour around the lake, leaving three men upon the island, to take 

 charge of the herd and to prepare the pack-saddles required for 

 our return to the States. 



The triangulation of this part of the survey occupied us until 

 the 16th, during which time the lake was again traversed in every 

 direction, and observations were taken from the various stations 



