Yosemite National Park’s Sierra Nevada yellow-legged frogs were so abundant in the mid-1800s that “it would be difficult to avoid stepping on them,” according to researcher Roland Knapp of ...

Knapp hopes that the rare success he and his ... was once the most abundant amphibian in the high elevations of the Sierra into one of the rarest. The scientists identified pockets of these ...

The general goal of Roland Knapp's research is to understand how natural and anthropogenic ... on are the result of his interest in a particular ecosystem: California’s Sierra Nevada. Despite the ...