This is probably the most dramatic picture of the whole series. It
is back at the point of initial impact. There are three parallel
tracks along the 'landing' line. The track shown here is the right
hand propeller just starting to bite the ground, and each blade took a
chunk out of the tundra and earth. The propeller track extends twenty
or thirty feet and then becomes a straight groove when the propeller
stopped turning. The blade strikes are about 18 inches apart. The other
two tracks were the airplane belly and the other propeller (not pictured).

I leave it as an excercise in mathematics to figure out the speed of
the hapless plane, assuming 2400 propeller rpm, three blades, each strike
18 inches apart. I did not take a measuring tape, so the 18 inches is
an educated guess.