Wimahl is a genus of cetacean that belongs to the family Kentriodontidae. It lived in the Miocene period. It contains a single species, Wimahl chinookensis. The name Wimahl translates to "big river" in the local Chinook language.
There is one known specimen. It includes a complete skull, some vertebrae, and parts of both flippers, and is labelled as UWBM 88078. It was found in 2003 near the north bank of the Columbia River, in Washington.[1]