A coalition that includes La Jolla's Birch Aquarium at Scripps released more than 3,000 endangered mountain yellow-legged frogs and tadpoles into the San Bernardino and San Jacinto mountains in 2026, pushing a 20-year breeding program past the 10,000-animal milestone.

San Diego Zoo Wildlife Alliance leads the effort from its Beckman Center for Conservation Research, where captive breeding began in 2006. Birch Aquarium is one of six partners in the program, alongside the U.S. Fish and Wildlife Service, U.S. Geological Survey, California Department of Fish and Wildlife, Omaha's Henry Doorly Zoo and Aquarium, and Big Bear Alpine Zoo, according to Fox 5 San Diego.

The mountain yellow-legged frog's population had declined by 98 percent before the program began. Disease, introduced predators, wildfires and drought drove the collapse.

Birch Aquarium joined the coalition in 2024 and raised more than 200 frogs from tadpoles to adults in its first year, according to the aquarium's newsroom. In August 2025, the aquarium completed its first-ever species reintroduction when 350 frogs were released into the San Bernardino Mountains. Of those, 220 were raised behind the scenes at Birch. Each frog was microchipped so scientists could track survival and growth.

Early results were promising. Frogs were documented at Bluff Lake for the first time since 1951.

The aquarium opened a new exhibition tied to the program on Friday, March 20, World Frog Day. Called "Imagine Wild: Mountain Yellow-legged Frog," the exhibit traces the species' decline and the science behind its reintroduction. Birch Aquarium serves more than 500,000 guests and 40,000-plus pre-K–12 students each year.

How many of the 3,000-plus animals released in 2026 were raised specifically at Birch Aquarium has not been disclosed. The coalition has now released more than 10,000 frogs and tadpoles into high-elevation habitats since 2006.

If you go: The Imagine Wild: Mountain Yellow-legged Frog exhibition is open at Birch Aquarium, 2300 Expedition Way, La Jolla. Visit aquarium.ucsd.edu for hours and tickets.