Mysterious sounds are very intriguing. My favorite is the mysterious sounds heard by Lewis and Clark on their expedition. This article goes down a bit of a rabb

Mysterious sounds are very intriguing. My favorite is the mysterious sounds heard by Lewis and Clark on their expedition. This article goes down a bit of a rabbit hole, but it starts with a fairly good summary: http://www.lewis-clark.org/article/1468 http://www.lewis-clark.org/article/1468