The following is an excerpt from Indian Tales of the Canadian Prairies (1894) by James Francis Sanderson.
How Medicine Hat was Named
There is a certain part of the South Saskatchewan River about a mile and a half from Medicine Hat, on which, even during the most severe winters, no ice forms. This opening in the river is regarded with great interest by the Indians, as it is believed to be the breathing place of the Great Spirit who lives in the river and who, when he shows himself, assumes the form of a serpent. As an indication of the widespread interest of the Indians in this particular spot, it may be mentioned that, during last winter which was more than usually severe, I was asked by the Blackfoot Indians whether it had frozen over. On learning that the opening was still there, the Indians evinced great delight. Had it been otherwise, they would have taken it as proof that the Great Spirit had either dried or gone elsewhere to some other breathing place.
Far back in Indian tradition, it is said that one of a hunting party of Blood Indians was sent forward to reconnoiter the country and see if buffalo were to be met with in any numbers. He was accompanied by his newly-married wife and a favorite dog, the latter bearing the travois- a crosspole arrangement to which the dog was harnessed- for the purpose of carrying some share of the travelling outfit.
One evening, the Indian camped by the river side and, as he was walking along near the opening in the river referred to, the serpent appeared to him and told him that if he would throw the flesh of his wife into the opening, he would become a great warrior and medicine man. The Indian returned to his tepee and repeated to his wife the words of the serpent. His wife at once expressed her willingness to die for the good of the tribe and in obedience to the call of the Great Spirit. Her husband, however, was reluctant and instead of his wife killed the dog. Carrying its carcass to the opening, he threw it in with the request that the Spirit might be pleased to accept from him his dog as a substitute for his wife. The Spirit refused to accept, and declared that, unless the Indian would sacrifice the wife, he could do nothing for hi. The man returned and informed his wife accordingly, and she again expressed her willingness to comply with the demand.
Finally, she was sacrificed and her flesh given to the Spirit, who then directed the man to stay all night on the island near by, to rise early next morning, and, as the sun rose, to proceed towards the cutbanks lying to the east. At the base of one of the cutbanks he would find a bag containing medicines and a hat trimmed with ermine. He was instructed to bring back the medicine bag and the hat with him to the Spirit who would explain the purpose of the hat and the efficacy of the medicines. The hat, he was told, was to be worn only in war, and would ensure victory to the wearer. The tradition had it that the Indian became famous as a medicine man and warrior.