Turning off the Jefferson, the trappers headed their canoe up a side stream, probably one of those marshy reaches where beavers have formed a swamp by damming up the current of a sluggish stream. Such quiet waters are favourite resorts for beaver and mink and marten and pekan. Setting their traps only after nightfall, the two men could not possibly have put out more than forty or fifty. Thirty traps are a heavy day's work for one man. Six prizes out of thirty are considered a wonderful run of luck; but the empty traps must be examined as carefully as the successful ones. Many that have been mauled, "scented" by a beaver scout and left, must be replaced. Others must have fresh bait; others, again, carried to better grounds where there are more game signs. Either this was a very lucky morning and the men were detained taking fresh pelts, or it was a very unlucky morning and the men had decided to trap farther up-stream; for when the mists began to rise, the hunters were still in their canoe. Leaving the beaver meadow, they continued paddling up-stream away from the Jefferson. A more hidden water-course they could hardly have found. The swampy beaver-runs narrowed, the shores rose higher and higher into rampart walls, and the dark-shadowed waters came leaping down in the lumpy, uneven runnels of a small cañon. You can always tell whether the waters of a cañon are compressed or not, whether they come from broad, swampy meadows or clear snow streams smaller than the cañon. The marsh waters roll down swift and black and turbid, raging against the crowding walls; the snow streams leap clear and foaming as champagne, and are in too great a hurry to stop and quarrel with the rocks. It is altogether likely these men recognised swampy water, and were ascending the cañon in search of a fresh beaver-marsh; or they would not have continued paddling six miles above the Jefferson with daylight growing plainer at every mile. First the mist rose like a smoky exhalation from the river; then it flaunted across the rampart walls in banners; then the far mountain peaks took form against the sky, islands in a sea of fog; then the cloud banks were floating in mid-heaven blindingly white from a sun that painted each cañon wall in the depths of the water. How much farther would the cañon lead? Should they go higher up or not? Was it wooded or clear plain above the walls? The man paused. What was that noise? "Like buffalo," said Potts. "Might be Blackfeet," answered Colter. No. What would Blackfeet be doing, riding at a pace to make such thunder so close to a cañon? It was only a buffalo herd stampeding on the annual southern run. Again Colter urged that the noise _might_ be from Indians. It would be safer for them to retreat at once. At which Potts wanted to know if Colter were afraid, using a stronger word--"coward."