The next day we continued down the river, which we were twice obliged to cross; and, the water having risen during the night, it was almost everywhere too deep to be forded. After traveling about sixteen miles, we encamped again on the left bank.
I obtained here an occultation of Scorpii at the dark limb of the moon, which gives for the longitude of the place 112° 18' 30", and the latitude 40° 18' 53".
JUNE.
1st.--We left to-day the Duchesne fork, and, after traversing a broken country for about sixteen miles, arrived at noon at another considerable branch, a river of great velocity, to which the trappers have improperly given the name of Lake fork. The name applied to it by the Indians signifies great swiftness, and is the same which they use to express the speed of a racehorse. It is spread out in various channels over several hundred yards, and is everywhere too deep and swift to be forded. At this season of the year, there is an uninterrupted noise from the large rocks which are rolled along the bed. After infinite difficulty, and the delay of a day, we succeeded in getting the stream bridged, and got over with the loss of one of our animals. Continuing our route across a broken country, of which the higher parts were rocky and timbered with cedar, and the lower parts covered with good grass, we reached, on the afternoon of the 3d, the Uintah fort, a trading-post belonging to Mr. A. Roubideau, on the principal fork of the Uintah river. We found the stream nearly as rapid and difficult as the Lake fork, divided into several channels, which were too broad to be bridged. With the aid of guides from the fort, we succeeded, with very great difficulty, in fording it, and encamped near the fort, which is situated a short distance above the junction of two branches which make the river.
By an immersion of the first satellite, (agreeing well with the result of the occultation observed at the Duchesne fork,) the longitude of the post is 109° 56' 42", the latitude 40° 27' 45".
It has a motley garrison of Canadian and Spanish engagés and hunters, with the usual number of Indian women. We obtained a small supply of sugar and coffee, with some dried meat and a cow, which was a very acceptable change from the pinoli on which we had subsisted for some weeks past. I strengthened my party at this place by the addition of Auguste Archambeau, an excellent voyageur and hunter, belonging to the class of Carson and Godey.
On the morning of the 5th we left the fort [Footnote: This fort was attacked and taken by a band of the Utah Indians since we passed it, and the men of the garrison killed--the women carried off. Mr. Roubideau, a trader of St. Louis, was absent, and so escaped the fate of the rest.] and the Uintah river, and continued our road over a broken country, which afforded, however, a rich addition to our botanical collection; and, after a march of 25 miles, were again checked by another stream, called Ashley's fork, where we were detained until noon of the next day.
An immersion of the second satellite gave for this place a longitude of 109° 27' 07", the latitude, by observation, being 40° 28' 07".
In the afternoon of the next day we succeeded in finding a ford; and, after traveling 15 miles, encamped high up on the mountain-side, where we found excellent and abundant grass, which we had not hitherto seen. A new species of elymus, which had a purgative and weakening effect upon the animals, had occurred abundantly since leaving the fort. From this point, by observation 7,300 feet above the sea, we had a view of Colorado below, shut up amongst rugged mountains, and which is the recipient of all the streams we had been crossing since we passed the rim of the Great Basin at the head of the Spanish fork.