Historical clue formulations

• Mountain lake — 2023-01-29
• Alpine lake — 2020-10-03
• Alpine lake — 2012-10-09
• Mountain lake — 2009-11-21
• Small mountain lake — 2005-04-30
• Lake formed by glaciation — 2003-04-20
• Mountain pool — 1999-03-18
• Mountain pool — 1998-08-13
• Mountain lake — 1998-05-03
• Mountain pool — 1994-09-11