Carrying with us the barometer and other instruments, in the afternoon we ascended to the highest point of the island--a bare, rocky peak, eight hundred feet above the lake. Standing on the summit, we enjoyed an extended view of the lake, enclosed in a basin of rugged mountains, which sometimes left marshy flats and extensive bottoms between them and the shore, and in other places came directly down into the water with bold and precipitous bluffs. Following with our glasses the irregular shores, we searched for some indications of a communication with other bodies of water, or the entrance of other rivers; but the distance was so great that we could make out nothing with certainty. To the southward, several peninsular mountains, 3,000 or 4,000 feet high, entered the lake, appearing, so far as the distance and our position enabled us to determine, to be connected by flats and low ridges with the mountains in the rear. These are probably the islands usually indicated on maps of this region as entirely detached from the shore. The season of our operations was when the waters were at their lowest stage. At the season of high waters in the spring, it is probable that the marshes and low grounds are overflowed, and the surface of the lake considerably greater. In several places the view was of unlimited extent--here and there a rocky islet appearing above the waters, at a great distance; and beyond, every thing was vague and undefined. As we looked over the vast expanse of water spread out beneath us, and strained our eyes along the silent shores over which hung so much doubt and uncertainty, and which were so full of interest to us, I could hardly repress the almost irresistible desire to continue our explorations; but the lengthening snow on the mountains was a plain indication of the advancing season, and our frail linen boat appeared so insecure that I was unwilling to trust our lives to the uncertainties of the lake. I therefore unwillingly resolved to terminate our survey here, and remain satisfied for the present with what we had been able to add to the unknown geography of the region. We felt pleasure, also, in remembering that we were the first who, in the traditionary annals of the country, had visited the islands, and broken, with the cheerful sound of human voices, the long solitude of the place. From the point where we were standing, the ground fell off on every side to the water, giving us a perfect view of the island, which is twelve or thirteen miles in circumference, being simply a rocky hill, on which there is neither water nor trees of any kind; although the Fremontia vermicularis, which was in great abundance, might easily be taken for timber at a distance. The plant seemed here to delight in a congenial air, growing in extraordinary luxuriance seven to eight feet high, and was very abundant on the upper parts of the island, where it was almost the only plant. This is eminently a saline shrub; its leaves have a salt taste; and it luxuriates in saline soils, where it is usually a characteristic. It is widely diffused over all this country. A chenopodiaceous shrub, which is a new species of OBIONE, (O. rigida, Torr. and Frem.,) was equally characteristic of the lower parts of the island. These two are the striking plants on the island, and belong to a class of plants which form a prominent feature in the vegetation of this country. On the lower parts of the island, also, a prickly pear of very large size was frequent. On the shore, near the water, was a woolly species of phaca; and a new species of umbelliferous plant (leptotæmia) was scattered about in very considerable abundance. These constituted all the vegetation that now appeared upon the island.
I accidentally left on the summit the brass cover to the object end of my spy-glass: and as it will probably remain there undisturbed by Indians, it will furnish matter of speculation to some future traveler. In our excursions about the island, we did not meet with any kind of animal; a magpie, and another larger bird, probably attracted by the smoke of our fire, paid us a visit from the shore, and were the only living things seen during our stay. The rock constituting the cliffs along the shore, where we were encamped, is a talcous rock, or steatite, with brown spar.
At sunset, the temperature was 70°. We had arrived just in time to obtain a meridian altitude of the sun, and other observations were obtained this evening, which placed our camp in latitude 41° 10' 42", and longitude 112° 21' 05" from Greenwich. From a discussion of the barometrical observations made during our stay on the shores of the lake, we have adopted 4,200 feet for its elevation above the Gulf of Mexico. In the first disappointment we felt from the dissipation of our dream of the fertile islands, I called this Disappointment island.
Out of the drift-wood, we made ourselves pleasant little lodges, open to the water; and, after having kindled large fires to excite the wonder of any straggling savage on the lake shores, lay down, for the first time in a long journey, in perfect security; no one thinking about his arms. The evening was extremely bright and pleasant; but the wind rose during the night, and the waves began to break heavily on the shore, making our island tremble. I had not expected in our inland journey to hear the roar of an ocean surf; and the strangeness of our situation, and the excitement we felt in the associated interest of the place, made this one of the most interesting nights I made during our long expedition.
In the morning, the surf was breaking heavily on the shore, and we were up early. The lake was dark and agitated, and we hurried through our scanty breakfast, and embarked--having first filled one of the buckets with water from the lake, of which it was intended to make salt. The sun had risen by the time we were ready to start; and it was blowing a strong gale of wind, almost directly off the shore, and raising a considerable sea, in which our boat strained very much. It roughened as we got away from the island, and it required all the efforts of the men to make any head against the wind and sea, the gale rising with the sun; and there was danger of being blown into one of the open reaches beyond the island. At the distance of half a mile from the beach, the depth of the water was 16 feet, with a clay bottom; but, as the working of the boat was very severe labor, and during the operation of sounding it was necessary to cease paddling, during which the boat lost considerable way, I was unwilling to discourage the men, and reluctantly gave up my intention of ascertaining the depth and the character of the bed. There was a general shout in the boat when we found ourselves in one fathom, and we soon after landed on a low point of mud, immediately under the butte of the peninsula, where we unloaded the boat, and carried the baggage about a quarter of a mile to firmer ground. We arrived just in time for meridian observation, and carried the barometer to the summit of the butte, which is 500 feet above the lake. Mr. Preuss set off on foot for the camp, which was about nine miles distant; Basil accompanying him, to bring back horses for the boat and baggage.
The rude-looking shelter we raised on the shore, our scattered baggage and boat lying on the beach, made quite a picture; and we called this the Fisherman's camp. Lynosiris graveolens, and another new species of OBIONE, (O. confertifolia--Torr. & Frem.,) were growing on the low grounds, with interspersed spots of an unwholesome salt grass, on a saline clay soil, with a few other plants.
The horses arrived late in the afternoon, by which time the gale had increased to such a height that a man could scarcely stand before it; and we were obliged to pack our baggage hastily, as the rising water of the lake had already reached the point where we were halted. Looking back as we rode off, we found the place of recent encampment entirely covered. The low plain through which we rode to the camp was covered with a compact growth of shrubs of extraordinary size and luxuriance. The soil was sandy and saline; flat places, resembling the beds of ponds, that were bare of vegetation, and covered with a powdery white salt, being interspersed among the shrubs. Artemisia tridentata was very abundant, but the plants were principally saline; a large and vigorous chenopodiaceous shrub, five to eight feet high, being characteristic, with Fremontia vermicularis, and a shrubby plant which seems to be a new salicornia. We reached the camp in time to escape a thunder-storm which blackened the sky, and were received with a discharge of the howitzer by the people, who, having been unable to see any thing of us on the lake, had begun to feel some uneasiness.
11th.--To-day we remained at this camp, in order to obtain some further observations, and to boil down the water which had been brought from the lake, for a supply of salt. Roughly evaporated over the fire, the five gallons of water yielded fourteen pints of very fine-grained and very white salt, of which the whole lake may be regarded as a saturated solution. A portion of the salt thus obtained has been subjected to analysis, giving, in 100 parts, the following proportions.
| Analysis of the salt. | |
| Chloride of sodium, (common salt,) | 97.80 |
| Chloride of calcium, | 0.61 |
| Chloride of magnesium, | 0.24 |
| Sulphate of soda, | 0.23 |
| Sulphate of lime, | 1.12 |
| 100.00 | |
Glancing your eye along the map, you will see a small stream entering Utah lake, south of the Spanish fork, and the first waters of that lake which our road of 1844 crosses in coming up from the southward. When I was on this stream with Mr. Walker in that year, he informed me that on the upper part of the river are immense beds of rock-salt of very great thickness, which he had frequently visited. Farther to the southward, the rivers which are affluent to the Colorado, such as the Rio Virgen, and Gila river, near their mouths, are impregnated with salt by the cliffs of rock-salt between which they pass. These mines occur in the same ridge in which, about 120 miles to the northward, and subsequently in their more immediate neighborhood, we discovered the fossils belonging to the oolitic period, and they are probably connected with that formation, and are the deposite from which the Great Lake obtains its salt. Had we remained longer, we should have found them in its bed, and in the mountains around its shores. By observation the latitude of this camp is 41° 15' 50", and longitude 112° 06" 43".