Historical clue formulations

• Ancestry — 2018-11-04
• Spelunker's activity — 2016-10-01
• Half of a mountaineering expedition — 2009-04-22
• Start of a trip in a bathysphere — 2007-07-29
• A ___ of woodpeckers — 2001-10-25
• Rocket maneuver — 2000-12-30
• Lineage — 1999-06-16
• Ancestry — 1995-12-10
• Ancestry — 1995-10-27
• Rappelling — 1994-06-25