I believe I read something similar to the final part of the Lummis/sacred-texts story, in my grandmother's old Manitoba reader. I don't think the farming was in it, though there may have been other tricks involving fishing or hunting. It was Fox advising Bear on ice fishing in that version. "Pull your tail up very fast, so you don't lose all the fishes." Fox leaves, while Bear waits patiently as the ice freezes around his tail. At last, Bear springs up, with such a jerk that his long tail breaks right off, leaving only the stub he has today.

The old Canadian readers contained several North American folktales, maybe from the Maritimes. (For instance, Glooscap getting the birds to dance in a circle with eyes shut, chanting "Whoever peeks will have red eyes." Suspicious, Grebe peeks, and seeing their host silently wringing necks of unsuspecting dancers, raises the alarm. Grebe's eyes are still red.) So, that Fox & Bear story, if traditional, could be an eastern version.