In all our journeying, we had never traveled through a country where the rivers were so abounding in falls; and the name of this stream is singularly characteristic. At every place where we come in the neighborhood of the river, is heard the roaring of falls. The rock along the banks of the stream, and the ledge over which it falls, is a scoriated basalt, with a bright metallic fracture. The stream goes over in one clear pitch, succeeded by a foaming cataract of several hundred yards. In a little bottom above the falls, a small stream discharges into an entonnoir, and disappears below.

We made an early encampment, and in the course of the evening Mr. Fitzpatrick joined us here with the lost mule. Our lodge-poles were nearly worn out, and we found here a handsome set, leaning against one of the trees, very white, and cleanly scraped. Had the owners been here, we would have purchased them; but as they were not, we merely left the old ones in their place, with a small quantity of tobacco.

6th.--The morning was frosty and clear. We continued up the stream on undulating forest ground, over which there was scattered much falling timber. We met here a village of Nez Perce Indians, who appeared to be coming down from the mountains, and had with them fine bands of horses. With them were a few Snake Indians of the root-digging species. From the forest we emerged into an open valley ten or twelve miles wide, through which the stream was flowing tranquilly, upwards of two hundred feet broad, with occasional islands, and bordered with fine broad bottoms. Crossing the river, which here issues from a great mountain ridge on the right, we continued up the southern and smaller branch over a level country, consisting of fine meadow-land, alternating with pine forests, and encamped on it early in the evening. A warm sunshine made the day pleasant.

7th.--To-day we had good traveling ground, the trail leading sometimes over rather sandy soils in the pine forest, and sometimes over meadow-land along the stream. The great beauty of the country in summer constantly suggested itself to our imaginations; and even now we found it beautiful, as we rode along these meadows, from half a mile to two miles wide. The rich soil and excellent water, surrounded by noble forests, make a picture that would delight the eye of a farmer.

I observed to-night an occultation of a Geminorum; which, although at the bright limb of the moon, appears to give a very good result, that has been adopted for the longitude. The occultation, observations of satellites, and our position deduced from daily surveys with the compass, agree remarkably well together, and mutually support and strengthen each other. The latitude of the camp is 43° 30' 36"; and longitude, deduced from the occultation, 121° 33' 50".

8th.--To-day we crossed the last branch of the Fall river, issuing, like all the others we had crossed, in a southwesterly direction from the mountains. Our direction was a little east of south, the trail leading constantly through pine forests. The soil was generally bare, consisting, in greater part, of a yellowish-white pumice-stone, producing varieties of magnificent pines, but not a blade of grass; and to-night our horses were obliged to do without food, and use snow for water. These pines are remarkable for the red color of the bolls; and among them occurs a species of which the Indians had informed me when leaving the Dalles. The unusual size of the cone (16 or 18 inches long) had attracted their attention; and they pointed it out to me among the curiosities of the country. They are more remarkable for their large diameter than their height, which usually averages only about 120 feet. The leaflets are short--only two or three inches long, and five in a sheath; the bark of a red color.

9th.--The trail leads always through splendid pine forests. Crossing dividing grounds by a very fine road, we descended very gently towards the south. The weather was pleasant, and we halted late. The soil was very much like that of yesterday; and on the surface of a hill near our encampment, were displayed beds of pumice-stone; but the soil produced no grass, and again the animals fared badly.

10th.--The country began to improve; and about eleven o'clock we reached a spring of cold water on the edge of a savannah, or grassy meadow, which our guides informed us was an arm of the Tlamath lake; and a few miles further we entered upon an extensive meadow, or lake of grass, surrounded by timbered mountains. This was the Tlamath lake. It was a picturesque and beautiful spot, and rendered more attractive to us by the abundant and excellent grass, which our animals, after traveling through pine forests, so much needed; but the broad sheet of water which constitutes a lake was not to be seen. Overlooking it, immediately west, were several snowy knobs, belonging to what we have considered a branch of the Cascade range. A low point, covered with pines, made out into the lake, which afforded us a good place for an encampment, and for the security of our horses, which were guarded in view on the open meadow. The character of courage and hostility attributed to the Indians in this quarter induced more than usual precaution; and, seeing smokes rising from the middle of the lake (or savannah) and along the opposite shores, I directed the howitzer to be fired. It was the first time our guides had seen it discharged; and the bursting of the shell at a distance, which was something like the second fire of the gun, amazed and bewildered them with delight. It inspired them with triumphant feelings; but on the camps at a distance the effect was different, for the smokes in the lake and on the shores immediately disappeared.

The point on which we were encamped forms, with the opposite eastern shore, a narrow neck, connecting the body of the lake with a deep cove or bay which receives the principal affluent stream, and over the greater part of which the water (or rather ice) was at this time dispersed in shallow pools. Among the grass, and scattered over the prairie lake, appeared to be similar marshes. It is simply a shallow basin, which, for a short period at the time of melting snows, is covered with water from the neighboring mountains; but this probably soon runs off, and leaves for the remainder of the year a green savannah, through the midst of which the river Tlamath, which flows to the ocean, winds its way to the outlet on the south-western side.

11th.--No Indians made their appearance, and I determined to pay them a visit. Accordingly the people were gathered together, and we rode out towards the village in the middle of the lake which one of our guides had previously visited. It could not be directly approached, as a large part of the lake appeared a marsh; and there were sheets of ice among the grass on which our horses could not keep their footing. We therefore followed the guide for a considerable distance along the forest; and then turned off towards the village, which we soon began to see was a few large huts, on the tops of which were collected the Indians. When we had arrived within half a mile of the village, two persons were seen advancing to meet us; and, to please the fancy of our guides, we ranged ourselves into a long line, riding abreast, while they galloped ahead to meet the strangers.