"The legs of this bear are somewhat longer than those of the black, as are it's tallons and tusks in comparably larger and longer....it's color is yellowish brown, the eyes small black and piercing."
--Meriwether Lewis on the grizzly bear.
Lewis and Clark heard rumors of the grizzly long before they first caught a glimpse of silver-tipped fur. Native Americans told stories of the bear's strength and resilience, and the explorers saw for themselves the massive tracks. By the time the Corps of Discovery had passed through what is now eastern Montana in the summer of 1805, the bears were no longer a mystery. They had encountered them swimming across rivers, running across the plains, and feeding on drowned bison. Grizzlies, it seemed, were everywhere.
Despite the bloodthirsty reputation that intrigued the explorers and the legends of ferocity that gave them the name Ursus arctos horribilus, grizzlies generally make their living from small fare. They may go after a moose or an elk, but the bulk of their diet is more humble: berries, moths, roots, grasses, pine nuts, salmon, and ants. With the exception of mothers with cubs, they largely live solitary lives, roaming over wide swaths of the western landscape. The distance they travel depends on the availability of food. A male grizzly's home range may extend up to 1,000 square miles.
Grizzlies gorge themselves in the fall, storing up precious fat for the winter. Bears typically sleep through the cold months in a cave or a hole left by an uprooted tree. In January through March, the females generally give birth to one or two cubs. As they emerge from their dens hungry in the spring, cubs learn from their mother how to identify food and where to find it. They spend up to three years with her, gathering information that will be valuable when they have to fend for themselves. The long rearing period, combined with small litters and high cub mortality, gives the grizzly bear the lowest reproduction rate of any animal in the Lower 48, making them particularly vulnerable to extinction.