n May 6, 1805, near the Milk River, in northeastern Montana, Meriwether Lewis revised his opinion of grizzlies once again. He referred to them as "gentlemen," that word denoting, in Lewis's lexicon of manners, a landowner. And those animals clearly were the undisputed sovereigns of the river bottoms.
|I find that the curiossity of our party is pretty well satisfied with rispect to this anamal, the formidable appearance of the male bear killed on the 5th added to the difficulty with which they die when even shot through the vital parts, has staggered the resolution of several of them, others however seem keen for action with the bear; I expect these gentlemen will give us some amusement sho[r]tly as they soon begin now to coppolate.|
Lewis must have learned of the bears' breeding schedule from the Mandan and Hidatsa Indians during the winter of 1804-1805, which is testimony both to the depth of his communication with residents along his route, and to the meticulous care he exercised in the collection of scientific data.
Indeed, the mating period extends from May to July. After a gestation period of 235 days, cubs are born in the hibernation dens in midwinter.
--Joseph Mussulman, 1999