motoged - 3-19-2020 at 09:37 AM
Some time ago some posts discussed rock formation fish traps along some coastal areas. British Columbia indigenous peoples used them and they still
serve a purpose....or porpoise:
https://www.cbc.ca/news/canada/british-columbia/killer-whale...
elgatoloco - 3-19-2020 at 09:50 AM
David K - 3-19-2020 at 12:57 PM
Along the ancient shoreline in the Imperial Valley desert, rocks were made into fish traps by long-ago tribes.
http://www.ivdesertmuseum.org/files/5214/2852/5354/Fish_Trap...
https://escholarship.org/content/qt1hk9f8px/qt1hk9f8px.pdf
http://www.sci.sdsu.edu/salton/AncientLakeCahuilla.html