The only male of the party frequently encircled the summit of the hill, as if to announce any danger to the females, which formed a group at the top.

Although they did not see Captain Lewis, the smell alarmed them, and they fled when he was at the distance of two hundred yards: he immediately ran to the spot where they had been; a ravine concealed them from him; but the next moment they appeared on a second ridge, at the distance of three miles.
He doubted whether they could be the same; but their number, and the extreme rapidity with which they continued their course, convinced him that they must have gone with a speed equal to that of the most distinguished race-horse.

Among our acquisitions to-day were a mule-deer, a magpie, a common deer, and buffalo: Captain Lewis also saw a hare, and killed a rattlesnake near the burrows of the barking squirrels." By "barking squirrels" the reader must understand that the animal better known as the prairie-dog is meant; and the mule-deer, as the explorers called it, was not a hybrid, but a deer with very long ears, better known afterwards as the black-tailed deer.
At the Big Bend of the Missouri, in the heart of what is now South Dakota, while camped on a sand-bar, the explorers had a startling experience.

"Shortly after midnight," says the journal, "the sleepers were startled by the sergeant on guard crying out that the sand-bar was sinking, and the alarm was timely given; for scarcely had they got off with the boats before the bank under which they had been lying fell in; and by the time the opposite shore was reached, the ground on which they had been encamped sunk also.

A man who was sent to step off the distance across the head of the bend, made it but two thousand yards, while its circuit is thirty miles." The next day, three Sioux boys swam the river and told them that two parties of their nation, one of eighty lodges, and one of sixty lodges, were camped up the river, waiting to have a palaver with the white explorers.