I poked around and found a little more information.
All the Tribes mentioned and associated with the term Parfleche seem to be Upper Plains and over to the Pacific Central and Northwest. Sioux, Cheyenne, and Crow are a few more. One reference also included Comanche.
An encyclopedia source cited the word as being of French Canadian origin, and listed the variation "Parflesh." Another term used for these is "Pa-Keep" bag. To me, this one seems like it could be a hybrid. "Pa" may be an Indian word, and "Keep" from English.
Use of the word Parfleche has apparently broadened to include anything made with stiff rawhide, including jewelry. Shapes are cut, painted, and fashioned into earrings and pendants. There are sources to purchase parfleche. It does not take modern paints, but the traditional pigments have been recreated. These recently became available on-line as well.
I had a pair of painted parfleche earrings my Mother gave me years ago, and tried to find them for a photo to include. They have disappeared, as things frequently do around here. Makes me wonder if there's a Little Person somewhere wearing them