DENVER (KDVR) — The Denver Zoo and Colorado Parks and Wildlife released nearly 600 Boreal toad tadpoles into a remote area of the Gunnison National Forest in hopes of increasing the population of the endangered species in the state.

The project began late last year when teams from both the zoo and CPW set up 95 adult toads from CPW’s Native Aquatic Species Restoration Facility in Alamosa for breeding.

“This was the result of a tremendous amount of hard work and planning by our partners at Colorado Parks & Wildlife, and members of our animal care and field conservation teams,” Senior Vice President for Conservation Engagement and Impact at Denver Zoo Erica Elvove said. “Boreal toads face an extremely uncertain future in Colorado and have a good chance of going extinct without human intervention. We’re committed to continuing this effort with CPW for many years to come, and doing our part to make sure the species remains part of Colorado’s ecosystem for future generations.”

The decline of the species is attributed to a fungus that can infect thousands of amphibian species. The decline has been excessive over the past two decades and officials estimate there may be as few as 800 wild adult boreal toads left in the state.

This isn’t the first endangered amphibian species the Denver Zoo has worked to conserve. It became the first zoo in the Northern Hemisphere to successfully breed critically endangered Lake Titicaca frogs. The zoo also bred 600 Boreal toads that were placed in Utah in 2019 and bred critically endangered Panamanian golden frogs.

CPW and the Denver Zoo believe it will be a multi-year program to get the Boreal toad population out of endangerment in the southern Rocky Mountains.

The zoo launched a community science project where volunteers keep track of the species’ high-country habitat to help document the survival of the population and determine the best locations to release them.