Historical clue formulations

• Native Oklahomans — 2026-04-12
• Plains tribe — 2018-02-18
• Plains Indians — 2014-11-12
• Plains Indians — 2014-07-30
• Oklahoma Indians — 2013-05-26
• Plains tribe — 2011-02-06
• Plains Indians — 2011-02-01
• Some Oklahomans — 2010-08-03
• Some Siouans — 2007-01-06
• Onetime Missouri natives — 2005-10-14
• Onetime Missouri tribe — 2003-10-12
• Siouan speakers — 2003-08-23
• Siouan speakers — 2002-06-08
• Oil-rich Indians — 2001-02-13
• Relatives of the Omaha — 2001-01-07
• Native Missourians — 2000-12-24
• Midwest Indians — 1997-10-11
• Plains Indians — 1996-02-01
• Plains Indians — 1994-07-19
• Some oranges — 1994-01-17