Updated on January 04, 2024

By the Saint Louis Zoo
Header image credit: Missouri Department of Conservation

In 2022, the Saint Louis Zoo Herpetology Department and the Saint Louis Zoo WildCare Institute Ron and Karen Goellner Center for Hellbender Conservation celebrated an incredible conservation milestone: The 10,000th zoo-raised hellbender was released to the wilds of Missouri’s Ozark plateau. This was a historic moment for our team and conservation partners as we take great pride in caring for this Missouri native.

Hellbender populations have declined by more than 70% over the last few decades, but we’ve come a long way since our release efforts began in 2008. This is thanks to the dedication of our team of zoo staff and collaborating biologists from the Missouri Department of Conservation (MDC) and U.S. Fish and Wildlife Service (USFWS).

An Ozark hellbender, orange and brown in color, sitting on a brown rock under water in a river.

This Ozark hellbender, like thousands of others, was raised at the Saint Louis Zoo and released into the wild.
Credit: Saint Louis Zoo


Saint Louis Zoo hellbender conservation

At the zoo, we support thousands of hellbenders, both Ozark and eastern subspecies, which are bred and raised for release into the wild to help bolster wild populations. Our conservation facility dedicated to these animals includes three stream systems that replicate conditions of wild Ozark streams and hundreds of smaller habitats used for rearing these special salamanders. Four full-time keepers care for hellbenders. In 2011, the zoo became the first institution to breed hellbenders and, in the years since, has provided rearing protocols to other Association of Zoos and Aquariums organizations wishing to work with hellbenders.

Justin Elden, curator of herpetology and and Jeff Dawson, zoological manager of herpetology, are proud to lead Saint Louis Zoo’s hellbender conservation efforts.

Justin Elden and Jeff Dawson of the Saint Louis Zoo, standing in a lab and smiling at the camera.

Justin Elden and Jeff Dawson of the Saint Louis Zoo.
Credit: Ray Meibaum | Saint Louis Zoo


“I started my zoo career caring for hellbenders,” Elden said. “I was just starting college and began working at the zoo on weekends to get hands-on experience in the world of conservation.”

“From a young age I wanted to do something in life to promote the conservation of wild animals and wild places. Hellbenders are some of the most fascinating animals on our planet. They have gone virtually unchanged for millennia and the fact that they live in our own state and our waterways is unbelievable. They are essentially living fossils. It’s a shame that they’re on the brink of extinction, and I want to do everything within our power to ensure they’re here for millennia to come.”

Elden added the day the 10,000th hellbender was returned to the wild was his first day as the zoo’s curator of herpetology.

“I was inundated with memories of being a college student, hoping someday these animals would be on the mend,” he said. “It is an incredible honor to be a small part of this program and begin the next chapter of my career with this milestone. To lead this charge with the remarkable keepers here at the zoo and our friends in the MDC and USFWS is a dream come true. I’m absolutely confident we will save this species.”

Three divers in wet suites with snorkels standing waist-deep in a river, one holding a hellbender that they are going to release.

MDC and Zoo staff release the 10,000th Ozark hellbender into an Ozark, Missouri river.
Credit: Missouri Department of Conservation


Dawson agreed the team’s successful hellbender conservation efforts are a great source of pride.

“Our efforts are not only helping to restore hellbenders to the wild in Missouri, but our work also serves as a model for groups working on this species in other states,” he said. “Our hellbender keepers are incredibly talented and dedicated, and I’m pleased that I can support their efforts by managing the day-to-day operations of the center. I look forward to the many opportunities presented by my new role at the zoo, which includes increasing my personal involvement with hellbender conservation.”

Our team has become successful at caring for both Ozark and eastern hellbenders, and this program is one of the most successful amphibian conservation programs in the world. This includes first- and second-generation animals bred in human care. Though these animals are endangered, it’s our hope, that with time and dedication, we will save this species from extinction, allowing Missouri residents to live side by side with them for years to come.

A clutch of eggs from an eastern hellbender.

These are the first clutch of eggs that first zoo-reared eastern hellbender successfully fathered in the wild, showing more hope for the species.
Credit: Jeff Briggler | Missouri Department of Conservation


Breaking hellbender news

Roughly a year after a zoo-reared Ozark hellbender successfully fathered a clutch of eggs in the wild, an eastern hellbender has followed suit.

MDC confirmed the first eastern hellbender raised in human care at the Saint Louis Zoo has reproduced in the wild on the Gasconade River. The news shows MDC’s partnership with the Saint Louis Zoo to recover hellbender populations is creating a bright future for the endangered Ozark and eastern hellbender in Missouri. This released male eastern hellbender originated from the fall 2015 collection of eggs on the Gasconade River by MDC, which was then transported to the Saint Louis Zoo where the eggs were hatched and reared. This male was released into the Gasconade River in June 2018.

Learn more about the eastern hellbender news.

Hellbender facts

  • Hellbenders are the largest species of amphibian in the U.S and one of the largest in the world.
  • They are are a fully aquatic salamander species.
  • They rely on fast-flowing and heavily oxygenated rivers and streams to survive.
  • They are at the top of the food chain in their habitat; the bulk of their diet is crayfish and small fish.
  • Hellbenders are a primitive amphibian species and have been part of Missouri’s rivers for millions of years.


Multiple hellbender tadpoles swimming in water.

These young hellbenders at the Saint Louis Zoo will continue to grow and will be released into the wild when they’re big enough.


The amazing work of the Saint Louis Zoo and its partners were featured on a recent episode on Mutual of Omaha’s Wild Kingdom Protecting the Wild, “Raising Hellbenders.” In the episode, Dr. Rae Wynn-Grant and Peter Gros travel to Missouri to see Ozark hellbenders in the wild and to meet the scientists who are breeding the species at the Saint Louis Zoo.

Check out this quick clip and get the full streaming link here.

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