Is the delicate way to mention the droppings from a Buffalo. You might ask why I would mention such a tidbit, well someone was asking so I looked it up. And yes if you are writing a story set in the plains during the 19th Century you'll want to know this little bit of info.
Buffalo chips—Last, but by no means least in value to tbe traveler ou the treeless plains, are the droppings of the buffalo, universally knowu as "buffalo chips." When over one year old and thoroughly dry, this material makes excellent fuel. Usually it occurs only where firewood is unobtainable, and thousands of frontiersmen have a million times found it of priceless value. When dry, it catches easily, burns readily, and makes a hot fire with but very little smoke, although it is rapidly consumed. Although not as good for a fire as even the poorest timber it is infinitely better than sagebrush, which, in the absence of chips, is often the traveler's last resort.
It usually happens that chips are most abundant in the sheltered creek-bottoms and near the water-holes, the very situations which travelers naturally select for their camps. In these spots the herds have gathered either for shelter in winter or for water in summer, and remained in a body for some hours. And now, when the cow-boy on the roundup, the surveyor, or hunter, who must camp out,.pitches his tent in the grassy coulee or narrow creek-bottom, his first care is to start out with his largest gunning bag to "rustle some buffalo chips" for a campfire. He, at least, when he returns well laden with the spoil of his humble chase, still has good reason to remember the departed herd with feelings of gratitude. Thus even the last remains of this most useful animal are utilized by man in providing for his own imperative wants.
Source: Report Upon the Condition and Progress of the U.S. National Museum ©1889