The orange-ish hue that can be seen in the waters here (as well as in many other waterfalls in the region) is caused by the high copper content in the surrounding rocks. The water dissolves some of that copper as it flows by, turning the water a coppery color.
The Ojibwe people were the first people to live in the area surrounding Kakabeka (as well as much of the area north and west of the Great Lakes), and they have a legend about the Falls involving a heroic Ojibwe princess named Green Mantle.
Green Mantle was the daughter of the Ojibwe chief White Bear. White Bear was an old and peaceful chief. He was greatly distressed when he learned that a band of Sioux warriors were making their way towards his tribe with the intention of attacking them. White Bear was to old to go to battle himself, and he was greatly worried that his tribe would lose the upcoming battle with the Sioux. Seeing her father's worry, Green Mantle came up with a plan to prevent the Sioux from reaching her people.
Having grown up in the area, Green Mantle was very familiar with the falls, the river, and the surrounding lands. She sneaked out of her village, took her canoe to the falls, and then paddled upstream from there until she reached the place where the Sioux were encamped. She bravely walked into their camp and when the Sioux spotted her, Green Mantle pretended to be lost and allowed them to capture her. She was then led before the Sioux chiefs, who threatened to execute her. She pretended to be very afraid at the prospect of losing her life and offered the Sioux a bargain. In exchange for sparing her life, she said, she would lead the Sioux to her tribe's village. Thinking this would give them an advantage over their enemy, the Sioux happily agreed.
Before the Sioux disembarked in their canoes the next morning Green Mantle suggested that they all tie their canoes together so that no one would get lost. Then they all traveled downriver, led by Green Mantle, towards tho Ojibwe village. Green Mantle, however, did not tell the Sioux about the falls. By the time the group had rounded the last river bend above the falls and the Sioux finally spotted them, it was too late. The river was moving too fast for the Sioux to paddle to shore, and the entire group plunged over the falls into the gorge below. Green Mantle lost her life that day along with the Sioux warriors, but in the process she saved the rest of her village from their attack.