While many people think of Buffalo Plaid as a statement from the American West, its origins in fact hail from the Rob Roy tartan of Clan McGregor in Scotland. A descendent of the Scottish clan ultimately settled in Montana and brought with him the classic textile. This relative traded heavy woven blankets in the style of his family's infamous black and raid plaid tartan for buffalo pelts, giving way to the nickname "buffalo plaid."
While we Americans refer to the pattern as plaid, the correct term is in fact tartan. It is said that the Cheyenne and Sioux warriors that traded with Jock McCluskey, the Scottish descendant in Montana, could not properly pronounce the Gaelic word pladger, meaning tartan, and instead referred to the textiles as plaid. The Indians were in awe of the deep red color in the original tartan and believed it to be dyed with the blood of McCluskey's prey and conquests. These American Indians wore this McGregor tartan in battle for protection and good luck.