SAN DIEGO — The Birch Aquarium is inviting visitors to hop into its newest exhibit opening today, Imagine Wild: Mountain Yellow-legged Frog.
The aquarium at the Scripps Institution of Oceanography at UC San Diego installed the immersive experience in place of the Meditation Ocean: Aquarius Reef Base exhibit, which opened in November and closed last month.
The new exhibit “transports guests to a fictional California mountainside to explore the forest, meadows and lake that form the Mountain Yellow-legged Frog habitat to discover their story of resilience, uncover the threats they face and learn how science and conservation are giving them a second chance,” according to a statement from the aquarium.
In 2024, Birch Aquarium joined an effort with the San Diego Zoo Wildlife Alliance, UCLA and other partners to raise more than 200 endangered mountain yellow-legged frogs from tadpoles to adults. The frogs were released in 2025 into the San Bernardino Mountains in a wildlife preserve managed by The Wildlands Conservancy.
It marked the first species reintroduction for Birch Aquarium.
“The return of the Mountain Yellow-legged Frog took decades,” said Robert Raad, senior exhibit designer at the Birch. “People with a clear vision worked to restore Southern California’s mountain habitats — believing they could be healthier, more resilient, and full of life. Imagine a place where endangered plants and animals thrive. We designed this space to let guests wander through that world — uncovering the dedication and perseverance that brought it back.”
The aquarium raised 220 of the frogs last year. The species is native to mountain ranges in Southern and Central California, with additional frogs raised by the San Diego Zoo Wildlife Alliance and UCLA.
Mountain yellow-legged frogs are small — between 1.6 and 3.5 inches long — with females typically larger than males. Their coloring ranges from yellowish to brown or olive with black or brown markings. The undersides of their hind legs can range from pale yellow to orange, giving them their common name. When handled, they can emit a defensive odor that smells strongly of garlic.
The exhibit invites visitors to explore the complex elements needed to create a healthy ecosystem for these endangered amphibians, while also highlighting the decadeslong effort to restore their habitat and the collaborative work involved in reintroducing the species.
Guests can conclude the experience by seeing some Birch-raised frogs up close.
Over the past century, about 90% of the species have been lost. Much of the decline has been attributed to introduced trout populations that feed on tadpoles. Other factors include pesticide exposure, a fungal disease and cattle ranching.
The species is divided into two population segments: a northern population listed as endangered since 2014 and a southern population listed in 2002. The first successful captive breeding of the frog occurred in 2009, when three tadpoles were raised at the San Diego Zoo.
Birch Aquarium opens daily at 9 a.m., with closing hours varying by day. More information is available at aquarium.ucsd.edu.
