Historical clue formulations

• Trees commonly confused with birches — 2025-12-07
• Utah's state trees — 2025-03-24
• Shakers in the woods — 2025-01-30
• Trees that form colonies from a single root system — 2023-11-23
• Rocky Mountain National Park sights — 2022-06-04
• White-barked trees — 2020-08-20
• "Quaking" trees — 2019-12-09
• Trees that "at the cross-roads talk together," in an Edward Thomas poem — 2019-11-30
• Ones trembling not out of fear — 2017-09-01
• Trembling trees — 2016-04-10
• Common sights in the Rockies — 2013-04-05
• Spectacular autumn trees — 2009-12-06
• Forest quakers — 2008-07-14
• Quakers in the woods — 2007-12-26
• Trembling trees — 2005-04-12
• Certain poplars — 2002-08-03
• Trembling trees — 2001-12-31
• Classic nature subjects for Ansel Adams — 2000-11-25
• Quakers — 2000-10-13
• Sights on ski slopes — 2000-01-02
• Quaking trees — 1999-05-16
• Trees with sawtooth-edged leaves — 1999-01-08
• Stand in the Rockies — 1996-09-12
• Quakers — 1994-06-12
• Quakers — 1994-02-09