Officials say the existence of the two southernmost populations of woodland caribou is in danger.
The Bonner County Daily Bee reports Bart George with the Kalispel Tribe at Usk says the next step to boost the populations -- comprised of seven animals including three in the southern Selkirk Mountains and four across the valley in the Purcell Mountains -- is not known.
George says the two populations don't intermix. The three cow population in the Selkirk spends more time on the Idaho side of the international border with Canada than the neighboring Purcell herd, which comprises three bulls and one cow.
Biologists had planned to herd the cows into birthing pens where they could calve and raise their young, but that plan was discarded when pregnancy tests of three cows that biologists hoped would reproduce came back negative.