The state's efforts to re-establish desert bighorn sheep in the Santa Catalina Mountains outside of Tucson has had a rough beginning, but now comes an optimistic sign for the herd.

"We have learned that we have two new lambs as of (Wednesday), and they are about a month old," said Raul Vega, Southern Arizona supervisor for Arizona Game and Fish.

He said the survival of the lambs shows the agency is on the right track.

"That's just to prove that they made it through a month and that is a really good sign," he said. "We're cautiously optimistic that this is going to work, and there's the proof there."

The gestation period for bighorns is six months, so among the 31 sheep released in November, there were at least two that were pregnant.

Ten of the sheep have died in past three months, most of them falling prey to mountain lions. Game and Fish has killed two lions to protect the sheep, and has restricted off-trail hiking in the Pusch Ridge area through April.

See a half-hour report on state efforts to re-establish the bighorn sheep herd and other endangered species on Arizona Week Friday at 6:30 p.m. on PBS-6.