Unusual knife--a tool for what?

[Ian]

I came across this knife many years ago in a yard sale in rural Minnesota. I did not know what it was used for, nor did the teenager who sold it to me after cleaning out his grandfather's barn.

Recently I discovered what this knife is used for. Does anyone else recognize it's function?

OAL = 16 inches
Blade = 10 inches

The blade has a sharpened beveled edge and is made from carbon steel.

Ian.

.