Mountain yellow-legged frog

The mountain yellow-legged frog numbered only 200 in isolated wild populations in 2010. Today, there are estimated to be roughly 1,000. (Rick Kuyper / U.S. Fish and Wildlife Service)

A federal proposal to make the Sierra Nevada as comfortable as possible for some of their rarest amphibian inhabitants has stirred a backlash from business owners over the economic pain it could cause the region’s recreation industry.

Many opponents worry the proposal would do more to protect frogs and toads than non-native trout --  a top tourist draw in mountain resort communities where cash registers ring up purchases this time of year made by vacationers, hikers and fishing enthusiasts.

The controversy hinges on a U.S. Fish and Wildlife Service proposal to designate roughly 2 million acres in 16 Northern California counties as critical habitat for the Sierra Nevada yellow-legged frog, the mountain yellow-legged frog and the Yosemite toad.

Since the 1960s, the amphibians have been decimated by fires, mudslides, pesticides, fungal infections and loss of habitat, as well as the appetites of nonnative predators such as brown, rainbow, brook and cutthroat trout.

The Sierra between roughly Mt. Whitney and Lake Tahoe was barren of trout until the 1800s, when mountaineers and prospectors began packing them in with milk cans and canvas bags.

Federal land-use and wildlife protection proposals are especially controversial in the eastern Sierras’ Inyo County, home to some of the best trout fishing streams in the state. Just 2% of the 10,000-square-mile region is privately owned, and 65% of the publicly owned land is already designated as wilderness.

“We get a little freaked out if someone takes tries to take one more acre away from what little is left for private and commercial development,” said Tawni Thomson, executive director of the Bishop Chamber of Commerce.

“So, we’re doing everything we can,” she added, “to encourage our members to make sure that decision makers know that, yes, the frogs are important -- but we have to balance that with the economic viability of our communities.”

Sarah Swenty, a spokeswoman for the Fish and Wildlife Service agrees, up to a point. “We can’t say the designation wouldn’t have any effect at all -- but we are not here to put anyone out of business,” Swenty said. “Essentially, a critical habitat designation identifies areas where a species of concern could survive and puts federal agencies on notice that they must take its needs into account when designing any project that requires a permit to proceed.”

In addition, she said, “it absolutely does not change ownership of the land. That stays the same.”

The Fish and Wildlife Service plans to release anticipated economic impacts of the proposal on Sept. 13.

Meanwhile, in Southern California, the mountain yellow-legged frog has made a remarkable leap toward recovery for an endangered species, federal biologists said.

In 2010, only 200 remained in isolated wild populations, prompting federal wildlife authorities and zoos in Fresno, Los Angeles and San Diego to launch an ambitious recovery program that included captive breeding facilities, trout removal programs and barring public access to areas where frogs were clinging to existence.

Today, the number of wild frogs scientists know as Rana muscosa is roughly 1,000, according to Robert Fisher, a research biologist with the U.S. Geological Survey.

Louis.Sahagun@latimes.com