The two men left among the Mandans to learn the language had returned to the Assiniboine River with more news of tribes from “the setting sun” who dwelt on salt water.  Pierre de la Verendrye went down to the Missouri with the two interpreters; but the Mandans refused to supply guides that year, and the young Frenchman came back to winter on the Assiniboine.  Here he made every preparation for another attempt to find the Western Sea by way of the Missouri.  On April 29, 1742, the two brothers, Pierre and Francois, left the Assiniboine with the two interpreters.  Their course led along the trail that for two hundred years was to be a famous highway between the Missouri and Hudson Bay.  Heading southwest, they followed the Souris River to the watershed of the Missouri, and in three weeks were once more the guests of the smoky Mandan lodges.  Round the inside walls of each circular hut ran berth beds of buffalo skin with trophies of the chase,—­hide-shields and weapons of war, fastened to the posts that separated berth from berth.  A common fire, with a family meat pot hanging above, occupied the centre of the lodge.  In one of these lodges the two brothers and their men were quartered.  The summer passed feasting with the Mandans and smoking the calumet of peace; but all was in vain.  The Missouri Indians were arrant cowards in the matter of war.  The terror of their existence was the Sioux.  The Mandans would not venture through Sioux territory to accompany the brothers in the search for the Western Sea.  At last two guides were obtained, who promised to conduct the French to a neighboring tribe that might know of the Western Sea.

[Illustration:  Fur Traders’ Boats towed down the Saskatchewan in the Summer of 1900.]

The party set out on horseback, travelling swiftly southwest and along the valley of the Little Missouri toward the Black Hills.  Here their course turned sharply west toward the Powder River country, past the southern bounds of the Yellowstone.  For three weeks they saw no sign of human existence.  Deer and antelope bounded over the parched alkali uplands.  Prairie dogs perched on top of their earth mounds, to watch the lonely riders pass; and all night the far howl of grayish forms on the offing of the starlit prairie told of prowling coyotes.  On the 11th of August the brothers camped on the Powder Hills.  Mounting to the crest of a cliff, they scanned far and wide for signs of the Indians whom the Mandans knew.  The valleys were desolate.  Kindling a signal-fire to attract any tribes that might be roaming, they built a hut and waited.  A month passed.  There was no answering signal.  One of the Mandan guides took himself off in fright.  On the fifth week a thin line of smoke rose against the distant sky.  The remaining Mandans went to reconnoitre and found a camp of Beaux Hommes, or Crows, who received the French well.  Obtaining fresh guides from the Crows and dismissing the Mandans,