E28: They Held On, Someone Stepped In: Bringing Back the California Red-Legged Frog, with Rob Grasso (Yosemite NP)

In this episode, I sit down with Yosemite National Park Aquatic Ecologist, Rob Grasso, to unpack the unlikely comeback of the California red-legged frog—a species that nearly vanished from the Sierra Nevada. From a childhood spent watching wetlands disappear in New Jersey to leading one of Yosemite National Park’s most ambitious restoration efforts, Rob shares the winding path that led him to this work—and the moment he realized there may be hope for these frogs after all. What follows is a story of persistence, partnership, and a bit of luck. We dig into the surprising history behind the frog’s decline, from overharvesting during the Gold Rush to invasive species and habitat loss, and explore how a hidden population in the foothills became the key to bringing them back. With the help of unlikely collaborators—including private landowners, the Yosemite Conservancy, and the San Francisco Zoo—thousands of frogs were carefully reared and reintroduced into Yosemite after a 70-year absence. But success wasn’t guaranteed. Rob walks us through the risks, setbacks, and small wins that defined the project—from the first frog released into the wild to the moment they realized the species was breeding again on its own. At its core, this episode is about more than just one frog. It’s about what happens when a species holds on just long enough for us to notice—and what it takes for us to step in and help it recover.