An Indian and his family were descending the Minnesota River when a few miles above present day Henderson they observed an immense fish which was spouting water from its head. It was spotted all over.

The Thunder Bird attacked it, hurling lightning at it as it continued down the river. The fish, the UN-KTE-HI, god of the waters and underworld, would dive and surface again and spout a mighty jet at the Thunder Bird. The Indians followed them to see the results of the battle. It continued for some three miles until near Henderson the huge fish became so enraged and maddened with pain by the incessant bolts of lightning that he tore his way headlong through the bank reentering the river two miles below. This place is now a sluggish channel called the Devil’s Elbow. Finding shelter in the bluff, his point of entry continues to send forth water to this day. Joseph Brown declares that when Henderson was laid out, there was no spring or ravine at that point where they both may be seen today.

Source:
Durand, Paul. Where the Waters Gather and the Rivers Meet. 1994