As we were riding slowly along this afternoon, clouds of dust in the ravines, among the hills to the right, suddenly attracted our attention, and in a few minutes column after column of buffalo came galloping down, making directly to the river. By the time the leading herds had reached the water, the prairie was darkened with the dense masses. Immediately before us, when the bands first came down into the valley, stretched an unbroken line, the head of which was lost among the river hills on the opposite side; and still they poured down from the ridge on our right. From hill to hill, the prairie bottom was certainly not less than two miles wide; and, allowing the animals to be ten feet apart, and only ten in a line, there were already eleven thousand in view. Some idea may thus be formed of their number when they had occupied the whole plain. In a short time they surrounded us on every side, extending for several miles in the rear, and forward as far as the eye could reach; leaving around us, as we advanced, an open space of only two or three hundred yards. This movement of the buffalo indicated to us the presence of Indians on the North fork.
I halted earlier than usual, about forty miles from the junction, and all hands were soon busily engaged in preparing a feast to celebrate the day. The kindness of our friends at St. Louis had provided us with a large supply of excellent preserves and rich fruit-cake; and when these were added to a macaroni soup, and variously prepared dishes of the choicest buffalo-meat, crowned with a cup of coffee, and enjoyed with prairie appetite, we felt, as we sat in barbaric luxury around our smoking supper on the grass, a greater sensation of enjoyment than the Roman epicure at his perfumed feast. But most of all it seemed to please our Indian friends, who, in the unrestrained enjoyment of the moment, demanded to know if our "medicine-days came often." No restraint was exercised at the hospitable board, and, to the great delight of his elders, our young Indian lad made himself extremely drunk.
Our encampment was within a few miles of the place where the road crosses to the North fork, and various reasons led me to divide my party at this point. The North fork was the principal object of my survey; but I was desirous to ascend the South branch, with a view of obtaining some astronomical positions, and determining the mouths of its tributaries as far as St. Vrain's fort, estimated to be some two hundred miles farther up the river, and near to Long's Peak. There I hoped to obtain some mules, which I found would be necessary to relieve my horses. In a military point of view, I was desirous to form some opinion of the country relative to the establishment of posts on a line connecting the settlements with the south pass of the Rocky Mountains, by way of the Arkansas and the South and Laramie forks of the Platte. Crossing the country northwestwardly from St. Vrain's fort, to the American Company's fort at the mouth of the Laramie, would give me some acquaintance with the affluents which head-in the mountain between the two; I therefore determined to set out the next morning, accompanied by four men--Maxwell, Bernier, Ayot, and Basil Lajeunesse. Our Cheyennes, whose village lay up this river, also decided to accompany us. The party I left in charge of Clement Lambert, with orders to cross to the North fork; and at some convenient place, near to the _Coulée des Frenes_, make a cache of every thing not absolutely necessary to the further progress of our expedition. From this point, using the most guarded precaution in his march through the country, he was to proceed to the American Company's fort at the mouth of the Laramie's fork, and await my arrival, which would be prior to the 16th, as on that and the following night would occur some occultations which I was desirous to obtain at that place.