Trilobites: Gray Ghosts, the Last Caribou in the Lower 48 States, Are ‘Functionally Extinct’ The herd of southern mountain caribou, the last in the contiguous United States, has dwindled to three animals. Conservationists attribute the decline to development in Canada. Share: Facebook Twitter Google+ Stumble Digg Email ThisBlogThis!Share to XShare to Facebook Related Posts:Q&A: Orchids Bloom in Thousands of Forms. But Why?Space weather warning: Alert as HUGE sunspot could cause TECH BLACKOUTMind: To Improve Memory, Tune It Like an OrchestraThe Diagnosis Is Alzheimer’s. But That’s Probably Not the Only Problem.SpaceX news: Falcon Heavy rocket UNVEILED in first official look at 27 engine spacecraftExpected Soon: First-Ever Photo of a Black Hole