The $2 billion Central Utah Project may find a three-inch frog an imposing barrier to finishing the Jordanelle Dam, government biologists say.

The once-abundant spotted frog seems to be disappearing at an alarming rate across the West, prompting U.S. Fish and Wildlife Service to take steps aimed at protecting the small amphibian under the Endangered Species Act."We want to seek protection for the species throughout its range," said James Miller, a Fish and Wildlife Service official in Denver.

Miller and several other scientists agree there may be a link between the declining spotted frog numbers and water projects like CUP, which includes the Jordanelle Dam six miles northeast of Heber City.

Miller is putting the final touches on a recommendation to add the spotted frog to the list of 19 imperiled amphibian species. He expects the report to be final in a month.

Both the frog and its marshy habitat would get federal protection under a "threatened" designation spanning the creature's range, from Alaska into the Rockies and south to Nevada.

The wildlife service's recommendation has not been submitted for final approval by the wildlife agency's administrators.

Under the 1973 endangered species law, federal dollars cannot be spent on a project that is likely to threaten the survival of a species. However, the law so far has not forced a large project to be scrapped - engineers usually find ways to minimize harm to the species.

There have been only a few times in which a protected species came close to blocking a project - the most publicized case involved the snail darter fish in Tennessee.

In 1979, Congress eventually overrode a series of decisions that asserted that to save the small darter, the Tellico Dam should not be built.

The Fish and Wildlife Service puts most of the blame for the spotted frog's hard times on natural predators, in particular the bullfrog and the leopard frog. Everywhere humans have brought in those species, spotted frogs have dwindled, biologists say.

But Peter Hovingh, a University of Utah biochemistry researcher and spare-time herpetologist, also believes water projects like CUP have dried up the frog's habitat and spurred its decline.

The Bureau of Reclamation, which is building CUP, has cited the lack of funding as the reason for not taking an inventory of the frog and other creatures, he noted in the May 1989 petition to the Fish and Wildlife Service.

Noting the petition was filed "with great reluctance," Hovingh said, "Major federal and state projects continue to ignore amphibious animals and their habitats."

"The multibillion-dollar federal project, the Central Utah Project, has affected more riparian habitat than any other project in Utah," Hovingh writes in the petition. "Yet (the bureau) refused to study the spotted frog or do an adequate wetland inventory . . . (and it) can thus destroy spotted frog habitat without a simple amphibian inventory."