Historical clue formulations

• Wide-open grassland — 2024-07-23
• Midwest expanse — 2020-11-04
• Some of the American heartland — 2020-04-26
• Badlands National Park feature — 2017-12-21
• With 11-Down, barking rodent — 2015-05-20
• Plain variety — 2014-07-12
• Flat land — 2012-06-27
• Sod house locale — 2012-02-26
• With 47-Down, Manitoba, Saskatchewan and Alberta — 2010-01-10
• Kansas expanse — 2007-07-09
• Pioneer's place — 2001-11-18
• Pronghorn antelope habitat — 2000-09-22
• Setting for Cather's "My Ántonia" — 1999-09-19
• Kind of dog — 1995-06-02
• Steppe — 1995-03-11