Tuesday, April 9.  We set off as soon as it was light, and proceeded five miles to breakfast, passing a low ground on the south, covered with groves of cottonwood timber.  At the distance of six miles, we reached on the north a hunting camp of Minnetarees consisting of thirty lodges, and built in the usual form of earth and timber.  Two miles and a quarter farther, comes in on the same side Miry creek, a small stream about ten yards wide, which, rising in some lakes near the Mouse river, passes through beautiful level fertile plains without timber in a direction nearly southwest; the banks near its entrance being steep, and rugged on both sides of the Missouri.  Three miles above this creek we came to a hunting party of Minnetarees, who had prepared a park or inclosure and were waiting the return of the antelope:  this animal, which in the autumn retires for food and shelter to the Black mountains during the winter, recross the river at this season of the year, and spread themselves through the plains on the north of the Missouri.  We halted and smoked a short time with them, and then proceeded on through handsome plains on each side of the river, and encamped at the distance of twenty-three and a half miles on the north side:  the day was clear and pleasant, the wind high from the south, but afterwards changed to a western steady breeze.  The bluffs which we passed to-day are upwards of one hundred feet high, composed of a mixture of yellow clay and sand, with many horizontal strata of carbonated wood resembling pit-coal, from one to five feet in depth, and scattered through the bluff at different elevations, some as high as eighty feet above the water:  the hills along the river are broken, and present every appearance of having been burned at some former period; great quantities of pumicestone and lava or rather earth, which seems to have been boiled and then hardened by exposure, being seen in many parts of these hills where they are broken and washed down into gullies by the rain and melting snow.  A great number of brants pass up the river:  there are some of them perfectly white, except the large feathers of the first and second joint of the wing which are black, though in every other characteristic they resemble common gray brant:  we also saw but could not procure an animal that burrows in the ground, and similar in every respect to the burrowing squirrel, except that it is only one third of its size.  This may be the animal whose works we have often seen in the plains and prairies; they resemble the labours of the salamander in the sand hills of South Carolina and Georgia, and like him, the animals rarely come above ground; they consist of a little hillock of ten or twelve pounds of loose ground which would seem to have been reversed from a pot, though no aperture is seen through which it could have been thrown:  on removing gently the earth, you discover that the soil has been broken in a circle of about an inch and a half diameter, where the ground is looser though