Historical clue formulations

• Mountain climber's aid — 2020-07-29
• Rock climber's tool — 2020-06-21
• Mountaineering spike — 2019-08-12
• Mountaineer's tool — 2018-11-30
• Climber's spike — 2018-01-16
• Climber's aid — 2016-09-09
• Climber's spike — 2015-07-12
• Climbing aid — 2011-09-25
• Rock climber's tool — 2007-01-31
• Cliff climber's tool — 2004-11-07
• Tool attached to a rope — 2001-04-01
• Climber's aid — 1999-05-01
• Climber's spike — 1998-12-27
• Scaler's spike — 1997-01-26
• Rock climber's spike — 1995-10-03
• Necessity for Hillary — 1995-06-21
• Mountain climber's spike — 1995-04-26
• Mountaineer's spike — 1995-01-31
• Alpinist's need — 1994-11-27