A pair of nearly extinct frogs have been found in Riverside County's San Jacinto Mountains, in an area where they hadn't been seen in nearly a half-century.

The discovery, coupled with this year's first successful captive breeding of a mountain yellow-legged frog in a North San Diego County laboratory, has given biologists fresh hope that one of Southern California's most endangered amphibians will live on.

"That's gigantic," Jeff Lemm, an animal research coordinator for San Diego Zoo's Institute for Conservation Research near Escondido, said of the finding in a telephone interview Monday. "It is just awesome news."

Lemm said the development is particularly gratifying at a time when amphibian news is being dominated by the extinction of dozens of frog species and with the demise of hundreds more threatened, as an African fungus called chytrid spreads unchecked.

"Amphibians are taking a beating worldwide," he said.

The discovery was made on two separate occasions, by different teams.

On June 10, a team of U.S. Geological Survey scientists found a mountain yellow-legged frog along Tahquitz Creek in the mountains near Idyllwild.

On June 25, biologists from the San Diego Natural History Museum found a yellow-legged frog along Willow Creek 2 1/2 miles away, while retracing the steps of a 1908 science expedition.

The locations are close to 8,000 feet above sea level in a wilderness area.

Scientists are encouraged, not only because of the finding, but because the habitat is more extensive than in the eight locations in the San Jacinto, San Bernardino and San Gabriel mountains where mountain yellow-legged frogs previously were known to exist.

And that could mean a large population exists along Tahquitz and Willow creeks.

"If this population is large, it could play an important role in the re-establishment of this species across Southern California," said Adam Backlin, the scientist who led the U.S. Geological Survey team.

Before the discovery, Geological Survey researchers had estimated the total population in the wild at 122 adults.

The species' condition had become so desperate that in August 2006, scientists enlisted the help of San Diego Zoo's Institute for Conservation Research to salvage 82 tadpoles from a dried-up stream in the same mountain range and launch the nation's first captive breeding program.

"Nobody's even kept these things in captivity before," Lemm said.

Of the tadpoles collected, 62 have survived to reach adulthood.

In a signature characteristic that distinguishes mountain yellow-legged frogs from many other frog species, the transformation to adulthood occurs gradually, Lemm said.

Because they live around cold, high-altitude waters and grow slowly, they remain tadpoles up to three years.

Once the tadpoles plucked from a canyon in the San Jacinto Mountains had become adults, they were ready for breeding.

Those frogs generated 200 eggs in December 2008, with three hatching into tiny tadpoles.

One of the babies has since grown into a froglet, or juvenile frog.

"We call him Han, short for Han Solo, because he's the only one," Lemm said. "He's doing great. He's growing and eating and doing everything that he's supposed to."

And before long, one of those things will be to mate.

Yellow-legged frogs normally breed March to June in their cool, high-altitude habitat.

But in much warmer Escondido, even with artificially chilled tanks, they began breeding in December last year, Lemm said.

He said they can be expected to start early again next winter.

By then, Han Solo should be ready to become an active participant in the breeding program.

"He will join the ranks," Lemm said.

Han Solo's ultimate destination could be to be reintroduced in the area of the new find.

"Either that or further surveys may reveal more frogs, and we may not have to put frogs back there," Lemm said.

Even before frogs are reintroduced into the wild, the 63 laboratory frogs will be split into smaller groups.

That's because the North County institute is about to get some help in the frog-raising task.

Lemm said permits are being secured to ship 20 frogs to Chaffee Zoological Gardens in Fresno, Lemm said. The Los Angeles Zoo and The Living Desert in the Palm Springs area are preparing to take 10 each.

Spreading the frogs around could prevent disease from wiping them out, and help the institute avoid the pitfalls of "keeping all of our eggs in one basket," Lemm said.

Call staff writer Dave Downey at 760-745-6611, ext. 2623.