The greatest risk of travelling after dark during the spring floods arose from what the _voyageurs_ called _embarras_--trees torn from the banks sticking in the soft bottom like derelicts with branches to entangle the trapper's craft; but the _embarras_ often befriended the solitary white man. Usually he slept on shore rolled in a buffalo-robe; but if Indian signs were fresh, he moored his canoe in mid-current and slept under hiding of the driftwood. Friendly Indians did not conceal themselves, but came to the river bank waving a buffalo-robe and spreading it out to signal a welcome to the white man; when the trapper would go ashore, whiff pipes with the chiefs and perhaps spend the night listening to the tales of exploits which each notch on the calumet typified. Incidents that meant nothing to other men were full of significance to the lone _voyageur_ through hostile lands. Always the spring floods drifted down numbers of dead buffalo; and the carrion birds sat on the trees of the shore with their wings spread out to dry in the sun. The sudden flacker of a rising flock betrayed something prowling in ambush on the bank; so did the splash of a snake from overhanging branches into the water. Different sorts of dangers beset the free trapper crossing the plains to the mountains. The fur company brigades always had escort of armed guard and provision packers. The free trappers went alone or in pairs, picketing horses to the saddle overlaid with a buffalo-robe for a pillow, cooking meals on chip fires, using a slow-burning wormwood bark for matches, and trusting their horses or dog to give the alarm if the bands of coyotes hovering through the night dusk approached too near. On the high rolling plains, hostiles could be descried at a distance, coming over the horizon head and top first like the peak of a sail, or emerging from the "coolies"--dried sloughs--like wolves from the earth. Enemies could be seen soon enough; but where could the trapper hide on bare prairie? He didn't attempt to hide. He simply set fire to the prairie and took refuge on the lee side. That device failing, he was at his enemies' mercy. On the plains, the greatest danger was from lack of water. At one season the trapper might know where to find good camping streams. The next year when he came to those streams they were dry.