Of all the dwellers in those western wilds the grizzly bears seemed most to object to the white strangers who prowled about their country. Unlike the Indians, the grizzlies attacked the explorers. The great, angry brutes rushed up and stood on their hind legs, threatening the strangers with wicked eyes and red, wide-open jaws, and striking with their great clumsy paws. Some of the party brought back big bearskins as trophies of their hairbreadth escapes. The buffalo were almost as eager to look at their white visitors as the strangers were curious about them. A few of the awkward beasts would follow the travelers about as if fascinated. One night a blundering buffalo bull came into the camp, sniffing right and left, between the rows of sleepers. The travelers waked up and tried to teach that big bison better manners than to call on strange gentlemen at such unseemly hours. The captains made several copies of the records of the trip and placed them in charge of different members of the party. One of these was carefully written on a kind of birch-bark paper which they believed would stand the hardest tests of time, dampness, and rough usage. They explored for a little distance up every river flowing into the Missouri and put down on their maps what they found out. They shot deer, antelope, and buffalo, and noted down what they could about all the small animals, and the birds, trees, fruits, flowers, soil, and minerals they found. It took the explorers nearly six months to examine sixteen hundred miles of the Missouri Valley. They went into winter quarters among the Mandan tribe of Indians, building a stockade like a high picket-fence of logs, with cabins inside, near where Bismarck, North Dakota, now stands, and naming it Fort Mandan.