20th.--We met a band of Utah Indians, headed by a well-known chief, who had obtained the American or English name of Walker, by which he is quoted and well known. They were all mounted, armed with rifles, and used their rifles well. The chief had a fusee, which he carried slung, in addition to his rifle. They were journeying slowly towards the Spanish trail, to levy their usual tribute upon the great California caravan. They were robbers of a higher order than those of the desert. They conducted their depredations with form, and under the color of trade and toll, for passing through their country. Instead of attacking and killing, they affect to purchase--taking the horses they like, and giving something nominal in return. The chief was quite civil to me. He was personally acquainted with his namesake, our guide, who made my name known to him. He knew of my expedition of 1842; and, as tokens of friendship, and proof that we had met, proposed an interchange of presents. We had no great store to choose out of; so he gave me a Mexican blanket, and I gave him a very fine one which I had obtained at Vancouver.

23d.--We reached Sevier river--the main tributary of the lake of the same name--which, deflecting from its northern course, here breaks from the mountains to enter the lake. It was really a fine river, from eight to twelve feet deep; and after searching in vain for a fordable place, we made little boats (or rather rafts) out of bulrushes, and ferried across. These rafts are readily made, and give a good conveyance across a river. The rushes are bound in bundles, and tied hard; the bundles are tied down upon poles, as close as they can be pressed, and fashioned like a boat, in being broader in the middle and pointed at the ends. The rushes, being tubular and jointed, are light and strong. The raft swims well, and is shoved along by poles, or paddled, or pushed and pulled by swimmers, or drawn by ropes. On this occasion, we used ropes--one at each end--and rapidly drew our little float backwards and forwards from shore to shore. The horses swam. At our place of crossing, which was the most northern point of its bend, the latitude was 39° 22' 19". The banks sustained the character for fertility and vegetation which we had seen for some days. The name of this river and lake was an indication of our approach to regions of which our people had been the explorers. It was probably named after some American trapper or hunter, and was the first American name we had met with since leaving the Columbia river. From the Dalles to the point where we turned across the Sierra Nevada, near 1,000 miles, we heard Indian names, and the greater part of the distance none; from Nueva Helvetia (Sacramento) to las Vegas de Santa Clara, about 1,000 more, all were Spanish; from the Mississippi to the Pacific, French and American or English were intermixed; and this prevalence of names indicates the national character of the first explorers.

We had here the misfortune to lose one of our people, François Badeau, who had been with me on both expeditions; during which he had always been one of my most faithful and efficient men. He was killed in drawing towards him a gun by the muzzle; the hammer being caught, discharged the gun, driving the ball through his head. We buried him on the banks of the river.

Crossing the next day a slight ridge along the river, we entered a handsome mountain valley covered with fine grass, and directed our course towards a high snowy peak, at the foot of which lay the Utah lake. On our right was a bed of high mountains, their summits covered with snow, constituting the dividing ridge between the Basin waters and those of the Colorado. At noon we fell in with a party of Utah Indians coming out of the mountain, and in the afternoon encamped on a tributary to the lake, which is separated from the waters of the Sevier by very slight dividing grounds.

Early the next day we came in sight of the lake; and, as we descended to the broad bottoms of the Spanish fork, three horsemen were seen galloping towards us, who proved to be Utah Indians--scouts from a village, which was encamped near the mouth of the river. They were armed with rifles, and their horses were in good condition. We encamped near them, on the Spanish fork, which is one of the principal tributaries to the lake. Finding the Indians troublesome, and desirous to remain here a day, we removed the next morning farther down the lake and encamped on a fertile bottom near the foot of the same mountainous ridge which borders the Great Salt lake, and along which we had journeyed the previous September. Here the principal plants in bloom were two, which were remarkable as affording to the Snake Indians--the one an abundant supply of food, and the other the most useful among the applications which they use for wounds. These were the kooyah plant, growing in fields of extraordinary luxuriance, and convollaria stellata, which, from the experience of Mr. Walker, is the best remedial plant known among these Indians. A few miles below us was another village of Indians, from which we obtained some fish--among them a few salmon trout, which were very much inferior in size to those along the Californian mountains. The season for taking them had not yet arrived; but the Indians were daily expecting them to come up out of the lake.

We had now accomplished an object we had in view when leaving the Dalles of the Columbia in November last: we had reached the Utah lake; but by a route very different from the one we had intended, and without sufficient time remaining to make the examinations which we desired. It is a lake of note in this country, under the dominion of the Utahs, who resort to it for fish. Its greatest breadth is about fifteen miles, stretching far to the north, narrowing as it goes, and connecting with the Great Salt lake. This is the report, which I believe to be correct; but it is fresh water, while the other is not only salt, but a saturated solution of salt; and here is a problem which requires to be solved. It is almost entirely surrounded by mountains, walled on the north and east by a high and snowy range, which supplies to it a fan of tributary streams. Among these, the principal river is the Timpan-ogo--signifying Rock river--a name which the rocky grandeur of its scenery, remarkable even in this country of rugged mountains, has obtained for it from the Indians. In the Utah language, og-wah-be, the term for river, when coupled with other words in common conversation, is usually abbreviated to ogo; timpan signifying rock. It is probable that this river furnished the name which on the older maps has been generally applied to the Great Salt lake; but for this I have preferred a name which will be regarded as highly characteristic, restricting to the river the descriptive term Timpan-ogo, and leaving for the lake into which it flows the name of the people who reside on its shores, and by which it is known throughout the country.

The volume of water afforded by the Timpan-ogo is probably equal to that of the Sevier river; and, at the time of our visit, there was only one place in the lake-valley at which the Spanish fork was fordable. In the cove of the mountains along its eastern shore, the lake is bordered by a plain, where the soil is generally good, and in greater part fertile; watered by a delta of prettily timbered streams. This would be an excellent locality for stock-farms; it is generally covered with good bunch-grass, and would abundantly produce the ordinary grains.

In arriving at the Utah lake, we had completed an immense circuit of twelve degrees diameter north and south, and ten degrees east and west; and found ourselves, in May, 1844, on the same sheet of water which we had left in September, 1843. The Utah is the southern limb of the Great Salt lake; and thus we had seen that remarkable sheet of water both at its northern and southern extremity, and were able to fix its position at these two points. The circuit which we had made, and which had cost us eight months of time, and 3,500 miles of traveling, had given us a view of Oregon and of North California from the Rocky mountains to the Pacific ocean, and of the two principal streams which form bays or harbors on the coast of that sea. Having completed this circuit, and being now about to turn the back upon the Pacific slope of our continent, and to recross the Rocky mountains, it is natural to look back upon our footsteps, and take some brief view of the leading features and general structure of the country we had traversed. These are peculiar and striking, and differ essentially from the Atlantic side of the country. The mountains all are higher, more numerous, and more distinctly defined in their ranges and directions; and, what is so contrary to the natural order of formations, one of these ranges, which is near the coast, (the Sierra Nevada and the Coast Range,) presents higher elevations and peaks than any which are to be found in the Rocky mountains themselves. In our eight months' circuit, we were never out of sight of snow; and the Sierra Nevada, where we crossed it, was near 2,000 feet higher than the South Pass in the Rocky mountains. In height, these mountains greatly exceed those of the Atlantic side, constantly presenting peaks which enter the region of eternal snow; and some of them volcanic, and in a frequent state of activity. They are seen at great distances, and guide the traveler in his course.

The course and elevation of these ranges give direction to the rivers and character to the coast. No great river does, or can, take its rise below the Cascade and Sierra Nevada range; the distance to the sea is too short to admit of it. The rivers of the San Francisco bay, which are the largest after the Columbia, are local to that bay, and lateral to the coast, having their sources about on a line with the Dalles of the Columbia, and running each in a valley of its own, between the Coast range and the Cascade and Sierra Nevada range. The Columbia is the only river which traverses the whole breadth of the country, breaking through all the ranges, and entering the sea. Drawing its waters from a section of ten degrees of latitude in the Rocky mountains, which are collected into one stream by three main forks (Lewis's, Clark's, and the North fork) near the centre of the Oregon valley, this great river thence proceeds by a single channel to the sea, while its three forks lead each to a pass in the mountains, which opens the way into the interior of the continent. This fact in relation to the rivers of this region, gives an immense value to the Columbia. Its mouth is the only inlet and outlet to and from the sea: its three forks lead to the passes in the mountains: it is, therefore, the only line of communication between the Pacific and the interior of North America; and all operations of war or commerce, of national or social intercourse, must be conducted upon it. This gives it a value beyond estimation, and would involve irreparable injury if lost. In this unity and concentration of its waters, the Pacific side of our continent differs entirely from the Atlantic side, where the waters of the Alleghany mountains are dispersed into many rivers, having their different entrances into the sea, and opening many lines of communication with the interior.

The Pacific coast is equally different from that of the Atlantic. The coast of the Atlantic is low and open, indented with numerous bays, sounds, and river estuaries, accessible everywhere, and opening by many channels into the heart of the country. The Pacific coast, on the contrary, is high and compact, with few bays, and but one that opens into the heart of the country. The immediate coast is what the seamen call iron-bound. A little within, it is skirted by two successive ranges of mountains, standing as ramparts between the sea and the interior of the country; and to get through which there is but one gate, and that narrow and easily defended. This structure of the coast, backed by these two ranges of mountains, with its concentration and unity of waters, gives to the country an immense military strength, and will probably render Oregon the most impregnable country in the world.