Historical clue formulations

• Abbr. in some city names — 2014-07-20
• Elevs. — 2013-12-04
• Mtn. stats — 2012-02-21
• Elevs. — 2009-06-23
• Elevs. — 2007-03-22
• Hills: Abbr. — 2005-06-11
• Abbr. used in some town names — 2003-12-05