Historical clue formulations

• One side of the border-straddling International Peace Garden — 2017-12-09
• Minnesota neighbor — 2013-04-17
• Home of Riding Mountain National Park — 2009-05-23
• Home for the Ojibwa and Cree — 2008-02-29
• Major nickel exporter — 2004-11-07
• Churchill is in it — 2003-07-18
• North Dakota neighbor — 1998-06-17