The existence of this one makes me purely happy, and surely there are all sorts of contexts in which one might want to fly a beaver flag! I purchased this from a seller in Illinois and believe the I.S.R likely stands for Ingersoll Scout Reservation in London Mills, IL, host to many a scout, though I have a hard time imagining that there have been many flags as good as this one that have emerged from troops staying there! Graphite and crayon on nice weight cotton worn soft now, with wood tipped cord ties still attached. I’d guess 1940s or so—definitely it has some nice age to it, and shows a little general soiling, more near the bottom, making me think perhaps it was flown over a Boy Scout bonfire! 

14 3/4" x 10 3/4" and in good condition, all the better for the years I think.