The Owens pupfish, Cyprinodon radiosus, is the largest of the pupfish species native to the California desert, reaching up to two inches in length. Once widespread up and down the Owens Valley in the network of ponds and sloughs that make up the Owens River watershed, the Owens pupfish was once a staple food item for the local Paiute, who caught fish by the hundreds and dried them for storage and later eating.

That bounty ended with the advent of European settlement and resource exploitation. Water diversions and introduced predatory fish such as largemouth bass depleted the Owens pupfish's numbers to the point where it was actually considered extinct by the mid-1940s.

Fortunately for the pupfish, a small group held on in a series of pools in Fish Slough, north of Bishop. Rediscovered in 1964, the fish were listed in 1967 as Endangered under the Endangered Species Preservation Act of 1966, a precursor to the current Endangered Species Act.

In 1969, as Fish Slough was drying up, those survivors were transplanted in a hurry to more hospitable locations. That hurried relocation provided what's likely one of the best California wildlife protection anecdotes ever. As biologist Edwin Philip Pister wrote in Natural History Magazine in 1993, he was alone when he realized a temporary holding pool in which every member of the species had been placed was actually killing the fish due to lack of oxygen. He literally loaded the total world population of Owens pupfish into two buckets and lugged them across the treacherous footing of Fish Slough.