How The World’s Rarest Fish Lives in the Hottest Place on Earth

What the film says

1. Devils Hole is a detached unit of Death Valley National Park in Nevada.

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2. Devils Hole pupfish have the smallest range of any vertebrate species.

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3. The bottom of Devils Hole has never been mapped; its actual depth is unknown.

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4. Large earthquakes as far away as Japan, Indonesia and Chile make the water in Devils Hole slosh.

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5. The first Devils Hole pupfish specimens were collected on the federal Death Valley Expedition in 1891.

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6. President Truman's 1952 proclamation added Devils Hole to Death Valley National Monument.

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7. In 1967, the ranch company Spring Meadows, Inc. began buying land in Ash Meadows.

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8. The Cappaerts' ranch covered about 12,000 acres and represented an investment of more than $7 million.

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9. The Cappaerts began pumping groundwater in 1968. Devils Hole had been stable at 1.2 ft below its marker; by 1972 it was 3.93 ft below, exposing the spawning shelf.

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10. UNLV biologist James Deacon helped found the Desert Fishes Council.

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11. In Cappaert v. United States, decided June 7, 1976, a unanimous Supreme Court held that reserving Devils Hole also reserved enough water to preserve the pool and its fish.

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12. Past counts peaked above 500 fish (1980, 1990, 1995) and fell to 35 in 2013.

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13. A 2022 genome study found extreme inbreeding in Devils Hole pupfish.

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14. The Ash Meadows Fish Conservation Facility was completed in 2013. It cost $4.5 million and holds a ~100,000-gallon replica of Devils Hole.

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15. The spring 2024 count of 191 fish was a 25-year high.

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16. Earthquakes in December 2024 and February 2025 sent waves through Devils Hole that washed algae and eggs off the spawning shelf.

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17. On December 5, 2024, a magnitude 7.0 earthquake struck offshore of Mendocino in Northern California.

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18. The spring 2025 count was 38 fish, down from 191 a year earlier (about 80%).

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19. For the first time, biologists added captive-raised fish (19 of them) to the wild population.

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20. Biologists count the fish twice a year, spring and fall, by scuba and from the surface.

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21. The Ash Meadows Amargosa pupfish lives in 10 spring areas, and the Warm Springs pupfish in six springs.

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22. A Pahrump newspaper editor threatened to throw the pesticide rotenone into Devils Hole to make the pupfish 'a moot point'.

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23. The Cappaert family sold their ranch in the late 1970s.

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