Historical clue formulations

• River that borders the Black Forest — 2025-12-14
• River alongside many German vineyards — 2024-07-01
• River forming the Swiss/Liechtenstein border — 2023-09-24
• Cologne's place — 2023-05-26
• Europe's Three Countries Bridge crosses it — 2022-02-27
• German river to the North Sea — 2021-10-11
• River near Rotterdam — 2020-11-29
• 760-mile river that starts in Switzerland — 2019-11-11
• River crossed in 1945's Operation Plunder — 2018-07-28
• River of Cologne — 2018-02-19
• Major river starting in SE Switzerland — 2017-05-24
• Locale of some Swiss banks — 2015-06-26
• ___-Main-Danube Canal — 2015-01-30
• Swiss/Austrian border river — 2014-10-15
• Type of white wine — 2014-09-06
• ___ Valley, German wine region — 2013-10-29
• German river whose valley is known for wine — 2011-07-25
• Lorelei's locale — 2010-12-12
• Liechtenstein's western border — 2010-09-26
• Cologne is found on it — 2010-05-01
• River straddled by Basel, Switzerland — 2009-07-05
• Riesling wines are produced in its valley — 2009-04-07
• Main outlet — 2006-06-23
• Schaffhausen's river — 2004-01-01
• German wine valley — 2003-07-28
• Kind of wine — 2002-07-20
• River past Liechtenstein — 2002-07-17
• Lorelei's river — 2002-04-24
• German wine valley — 2001-05-07
• River through Switzerland — 1999-02-03
• Kind of wine — 1997-04-08
• View from Basel — 1996-01-26