Reasons for the name vary
Legends says that when viewed from the south, the landform known as the ‘Turtle Mountains’ appeared to the Anishinaabe as a turtle on the horizon with the head pointing westward and the tail to the east.
Another legend says that the Turtle Mountains were named for a man named “Mickinock” (turtle) who walked (or ran) its entire length in one day.
Other names given to the Turtle Mountains include Makinak Wudjiw (Turtle Mountain in Ojibwemowin), LaMontagne Tortue (Michif for ‘Turtle Mountain’), Turtle Hill, Beckoning Hills, and the Blue Jewel of the Plains.
Patrick Gourneau, in his book History of the Turtle Mountain Chippewa explained why “Turtle Mountain” is not “Turtle Mountains.” He states the following:
“The naming of Turtle Mountain goes back a long time, versions from white men and Indians. To mention only three Chippeway versions, it indicates that it was the early Chippeway migrants from the woodlands of the east who named it Turtle Mountain. None of the three versions carry the name Turtle Mountains. As far back as my memory goes, I have not ever heard a full-blood term the hills as Turtle Mountains, and same applies to the “Mechifs.” The Chippeway name is “Mekinauk Wudjiw” (Turtle Mountain). If it was Turtle Mountains it would be “Mekinauk Wudjiw wum” (plural).
History of the Turtle Mountain Band of Chippewa Indians Paperback – 1989 by Patrick Gourneau