The other two rivers, the Pishon and the Gihon, however, are unidentified.​—See CUSH No. 2; HAVILAH No. 1.

Some, such as Calvin and Delitzsch, have argued in favor of Eden’s situation somewhere near the head of the Persian Gulf in Lower Mesopotamia, approximately at the place where the Tigris and the Euphrates draw near together. They associated the Pishon and Gihon with canals between these streams. However, this would make these rivers tributaries, rather than branches dividing off from an original source.

the impossibility of definitely determining the identification of the Pishon and Gihon rivers, is possibly explained by the effects of the Noachian Flood, which undoubtedly altered considerably the topographical features of the earth, filling in the courses of some rivers and creating others.