Lewis and Clark found the plains fairly swarming with wildlife, and not just with “musquetoes,” either. Just upstream from the confluence of the Missouri and Yellowstone Rivers, Lewis noted:
The whole face of the country was covered with herds of Buffaloe, Elk & Antelopes; deer are also abundant, but keep themselves more concealed in the woodland. the buffaloe Elk and Antelope are so gentle that we pass near them while feeding, without appearing to excite any alarm among them; and when we attract their attention, they frequently approach us more nearly to discover what we are, and in some instances pursue us to a considerable distance apparently with that view.
They also reported encounters with rattlesnakes, wolves, black bears, grizzlies, beavers (one of which gave Lewis’s dog a nasty bite), bighorn sheep (whose meat was reportedly a delicacy), a “polecat” (skunk), mule deer, and prairie dogs. On their trip up the Missouri, Lewis provided the first descriptions of the sage grouse, the western meadowlark, and the cutthroat trout.
The buffalo, bears, and wolves may be mostly gone from the prairies, but what Lewis called “our trio of pests”—mosquitoes, gnats, and prickly pear—remain.
Prairie life calls for adaptation, and many animals that live here dig burrows. Witness the prairie dog. It can metabolize its own waste water and survive for years without drinking. The black-tailed prairie dogs of Montana live in “towns” of burrows, which are occasionally sublet by burrowing owls.
Another burrowing animal is the pocket gopher, a long-clawed, small-eyed rodent that comes aboveground only for quick passes at mating. Pocket gophers get their nutrition—both food and water—from plants they suck, roots first, into their burrows.
While burrows may provide defense for many rodents and birds, the pronghorn relies on fleetness. Individuals have been clocked at 70 miles per hour. Their horn is part of a sheath composed of keratin (a fingernail-like protein) and fused hairs covering a core of bone. Pronghorns (which despite the common appellation are not antelopes) shed their horn sheaths annually and pass the winter and spring sporting the bare bony horn core. They are the only mammals that shed their horns (as opposed to antlers, which are, as a rule, dropped annually).
Deer, both white-tailed and the large-eared mule deer, roam the breaks of the big eastern Montana rivers. Coyotes still prey on both wild and stock animals. Gray wolves, edging in from Canada and Minnesota, have returned to the badlands of the Missouri River in recent years.
Rattlesnakes can turn up just about anywhere in eastern Montana, and it pays to watch where you put your hands and feet. Wear sturdy shoes for hiking. Although healthy adults rarely die from a rattlesnake’s venom, a bite does warrant prompt medical attention.
There’s abundant insect life on the prairie. Most everyone who’s read a Western novel can conjure an image of grasshoppers scouring the grasslands and swarming around cattle, cowboys, and horses.
Although magpies seem to control Montana’s airways, the sharp-tailed grouse, mourning dove, killdeer, bobolink, long-billed curlew, horned lark, western meadowlark, goldfinch, Brewer’s blackbird, and sparrow hawk are all birds to be spotted above the eastern Montana plains.
Warm-water species of fish, such as paddlefish, walleye, northern pike, and channel catfish, inhabit the Yellowstone and the Missouri as they cross the plains.
© W.C. McRae & Judy Jewell from Moon Montana, 7th Edition