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 [now dead]
Posted to by Jim Weller (in Yellowknife)