898 METEOROLOGY OF ROUTE FROM FORT BENTON TO WALLAH-WALLAH. 
having laid in a new supply of provisions, on the 30th lefi Fort Owen. The weather for the last 
few days had become much milder, and the snow had all disappeared from the valley, and the 
ice had mostly left the river. We followed down the Bitter Root river to its junction with Hell 
Gate fork, and crossed the latter on the evening of the 31st. On the 1st of February, in our gen- 
eral course down the stream formed by the junction of the Blackfoot and Hell Gate forks, we 
passed through the defile of Coriacah, in which a few inches of snow were found. From this 
point to Thompson’s prairie our course lay mostly through mountain defiles and small prairies. 
We arrived at the above-named prairie on the night of the 5th. 
From Fort Owen up to this point there had been no snow except on the mountain-tops, and in 
the defile before mentioned grass had been very good ; and in the numerous small prairies, among 
which Camash prairie and Horse plain may be mentioned, herds of Indian horses, which had been 
left there by their owners to winter, were grazing, all in fine condition. On Thompson’s prairie 
there was an unusual number of them, for this had been made the depot for the horses of all 
travelling west this season, under the impression that they would be unable to take them farther, 
on account of snow and want of grass. The latter obstacle I had partially prepared for by taking 
along a few bushels of grain. From the morning of the 7th to the night of the 15th, when we 
camped near the Pend d’Oreille lake, our general course was down the Flathead river through a 
densely-wooded country, perfectly devoid of grass even in the summer. The snow had gradually 
increased in depth from Thompson’s prairie for about fifty miles west, when it had reached the 
depth. of two feet on an average, and remained about this depth to within a few miles of Pend 
d’Oreille lake, when it began to decrease, and in the immediate vicinity of the lake was not over 
one foot in depth. The travelling for the last seven days had been severe on the animals, though 
none of them had given out, notwithstanding their want of feed. As we continued westward 
along the lake-shore the snow continued to decrease, and now and then a fine field of grass was 
found. 
On the 17th a mule and a horse gave out, and I was obliged to leave them, which I did, in good 
grass. On the 18th crossed Clark’s fork of the Columbia, which was nearly clear of ice; and on 
the 19th commenced the passage from the river to the Coeur d’Alene prairie, a distance of about 
sixty miles. This distance we intended to make in two days, but our guide was unable to follow 
the trail on account of snow, and consequently we did not reach the prairie tll the night of the 
22d. The travelling was worse these last four days than it ever had been before. The snow for 
most of the way was two and a half feet deep, and very hard. The forest was dense, and grass 
exceedingly scarce. As we left this forest we left the snow for the last time. The prairie was 
covered with fine grass, and the stock on this plain was in nearly as good condition as that in the 
Flathead country. 
Here I was obliged to procure a relay of borses and Jeave mine, for they were entirely unable 
to continue on to Wallah-Wallah. With fresh animals the Spokane prairie is seven travelling 
days from Wallah-Wallah, and as the travelling was good, and the streams mostly were fordable, 
we arrived there on the 2d of March. We found no lack of grass at any point. On the 3d we 
continued on down the Columbia, and arrived at the Dalles early on the 7th. Grass here, at this 
season of the year, may be considered fair, but I should judge it would be very scarce in the 
season of emigration. The principal feature of the weather, since leaving the Flathead village, 
has been its dampness and storminess; scarcely a day passed, during the whole time, that was 
entirely pleasant. 
The above statement I have endeavored to make as short as possible, and, at the same time, 
to contain all that relates to the subject in question. Ihave not noticed, in any manner, the 
topography or resources of the country, or what I saw of the manners or customs of the 
Indians, as you have already all those things before you. 
Very respectfully, C. GROVER. 
His Excellency I. I. Sruvens, Governor of Washington Territory. 
