http://paleofood.com/recipes/pemmican-pemmicanhowtomake.htm
The text below is an excerpt from a larger article located at the link above.
When the white men set out across North America, a reliable supply of portable provisions was one of the major problems. Lacking the skills of the native hunters, it was doubtful that they could live off the country. They knew something about preserving food, a necessity for sailing ships, but it was limited to salting and pickling. The resultant salt pork and hardtack were unappetizing fare but they kept life in a man. The Plains Indians had a better solution to the problem, and one on which the fur traders and explorers came to depend. The answer was pemmican. The Cree word Pimikan meant, roughly, manufactured grease, but there was a lot more than that to it. Basically it was buffalo meat, cut with the grain in thin slices or strips and dried in the sun or over a slow fire. A smoking fire added flavor and was useful for keeping the flies off though if meat racks were high they tended to be clear of flies. The dry-meat was then spread on a hide and pounded by stones or mallets to become "beat meat" which was tossed into a rectangular rawhide container (hair on the outside) about the size of a flour sack. To the dehydrated, crumbled meat was added one-third or more of melted fat and the bag was sewn up. The fat might be mixed with the meat before or after it was bagged. While the pemmican was cooling the bag was turned from time to time to prevent the fat all settling on one side. Compressed in a skin bag that was greased along the seams to eliminate air and moisture, it would keep for years. In the best pemmican, which was limited in quantity, the meat was very finely pulverized and only marrowfat, from boiled broken bones, was used. For variety and flavour dried fruits such as chokecherries, Saskatoon or Service berries might be added. The pemmican bags were flattened for easier handling. At times, rendered fat was stored in rawhide bags, left in a round shape to distinguish them from the pemmican bags. Marrow, while better tasting, was comparatively scarce and did not keep as well as ordinary tallow and would be preserved in bladders. The bags of pemmican weighed 80 to 90 pounds and it was estimated that each bag accounted for two buffalo (bison). So high was the food value that three-quarters of a pound was a reasonable day's ration but hard working voyageurs were more likely to consume between one and two pounds each in a day. Moose and elk meat was sometimes treated similarly but the results were not so satisfactory. In some regions fish pemmican was made by pounding dried fish, mixed often with sturgeon oil, but it was more usual, as it is now among the Crees, for the pounded fish and the fish oil to be kept separately, the oil in animal bladders. David Thompson in 1810, described pemmican in detail: "...dried provisions made of the meat and fat of the bison under the name of pemmican, a wholesome, well tasted nutritious food, upon which all persons engaged in the fur trade mostly depend for their subsistence during the open season; it is made of the lean and fleshy parts of the bison dried, smoked and pounded fine: in this state it is called beat meat: the fat of the bison is of two qualities, called hard and soft;...the latter...when carefully melted resembles butter in softness and sweetness. Pemmican is made up in bags of ninety pounds weight, made of the parchment hide of the bison with the hair on; the proportion of the Pemmican when best made for keeping is twenty pounds of soft and the same of hard fat, slowly melted together, and at a low warmth poured on fifty pounds of beat meat, well mixed together, and closely packed in a bag of about thirty inches in length, by near twenty inches in breadth, and about four in thickness which makes them flat, the best shape for stowage and carriage...I have dwelt on the above, as it (is) the staple food of all persons, and affords the most nourishment in the least space and weight, even the gluttonous French Canadian (the voyageurs) that devours eight pounds of fresh meat every day is contented with one and a half pounds per day: it would be admirable provision for the Army and Navy." By Dorthea Calverley http://www.calverley.dawson-creek.bc.ca/Part01-FirstNations/ [now dead] Posted to rec.food.preserving by Jim Weller (in Yellowknife)