Pipe dance Assiniboin by George Catlin Assiniboin (Chippewa: u'sini, stone' u'pw銤a 'he cooks by roasting': 'one who cooks by the use of stones.'-W. J.). A large Siouan tribe, originally constituting a part of the Yanktonai. Their separation from the parent stem, to judge by the slight dialectal difference in the language, could not have greatly preceded the appearance of the whites, but it must have taken place before 1640, as the Jesuit Relation for that year mentions the Assiniboin as distinct. The Relation of 1658 places them in the vicinity of Lake Alimibeg, between Lake Superior and Hudson bay. On Jefferys' map of 1762 this name is applied to Lake Nipigon, and on De l'Isle's map of 1703 to Rainy lake.