The Pi-a-saw Bird

In 1673 the first European explorers to travel down the Mississippi River spot on the high, sheer bluffs the painting of a huge, winged monster. Where does it come from?Why did somebody take the trouble and risk to paint it on the bluff face? The Indians told them the terrifying story of a man-eating dragon-like creature, and the brave chief who killed it. This historical, Native American dragon fantasy short story previously published in FANTASTIC December 1975, and unavailable since then, until now.
We know dragon stories and legends from Europe and Asia go back thousands of years. Did some such creature prey on people just north of modern-day St. Louis? A dragon in North America?The French explorers Pere Marquette and Joliet paddle their canoes down the Father of Waters, the first Europeans to journey through the middle of the newly discovered continent of North America. They spot the painting.
Why did some unnamed Indian artist risk their life to create it? The perpendicular bluffs rise up from the river hundreds of feet high. Other Indians must have lowered the artist on a rope from the top, and the artist dangled above the rocks of the rivershore as they worked. Canoes of Indian warriors pass the explorers on the river. As they pass the painting of the dragon-like, flying monster, they shoot arrows at the Indian dragon.
A certain loss of good arrows, because they break or bounce off the white limestone rock of the bluff and fall into the river. What frightens the Indians so much?