(AP) — A grizzly bear attacked and killed a 38-year-old mountain biker as he was riding along a trail just outside Glacier National Park, Montana authorities said. Authorities have closed the area, which is about 3 miles away from Glacier's west entrance, for public safety. Grizzlies in the Lower 48 states have been designated a threatened species since the 1970s, but their numbers are increasing and so are conflicts between humans and bears. In the most well-known Glacier attacks, bears killed two people in different parts of the park in a single night in 1967.