Death Valley National Park in the Mojave Desert regularly exceeds 100 degrees Fahrenheit (37.8 degrees Celsius).
Despite the extreme temperatures, one species of fish -- the Devils Hole pupfish -- has survived here in a deep underwater cave, also called Devils Hole, for thousands of years.
Devils Hole could easily be missed when you're traveling the largely unmarked desert roads.
High walls of limestone hide Devils Hole from the road.
Starting in the 1960s, groundwater pumping in the Devils Hole area caused the cave's water levels to drop. This damaged the pupfish's natural habitat, making it difficult for the now-endangered species to maintain its numbers.
At latest count, 87 pupfish live in Devils Hole today, up from its all-time low of 35 adult pupfish in 2013, but down from their historical numbers of 450 in the fall and 250 in the spring (the seasonal variation is normal).
To get an accurate estimate of the number of pupfish in Devils Hole, divers like University of Nevada Las Vegas professor, Stan Hillyard, explore the cave.
Divers have descended 436 feet into Devils Hole, but haven't yet found the bottom. Despite is incredible depths, Devils Hole pupfish live in the top 80 feet of the cave.
National Park Service aquatic ecologist, Kevin Wilson, is part of a team trying to restore the population of Devils Hole pupfish.
Solar arrays power much of the equipment used in and around Devils Hole.
A weather station next to Devils Hole, also solar-powered, tracks wind speed, precipitation, temperature and humidity.
Wilson feeds the Devils Hole pupfish, who rely heavily on the shallow shelf near the water's surface for survival. Now that the water levels are lower, the shallow shelf doesn't provide as much support to the fish as before.
The 110,000-gallon Ash Meadows Fish Conservation Facility near Devils Hole re-creates the conditions in the underwater cave. This enables scientists and other staff to establish a "lifeboat" population of the endangered fish.
The team at the Ash Meadows Fish Conservation Facility relies on programmed software to track the conditions inside the replica tank. They monitor it closely to make sure the habitat is just right for the critically endangered fish.
The system also allows the team to watch the pupfish in real time from their computer screens.
Currently, 100 Devils Hole pupfish live at the Ash Meadows Fish Conservation Facility.