On the mountain ranges and outliers the soils are mostly derived from the underlying hard bedrock and are too steep and stony to be cultivated. In Great Plains Montana the soils south of the limit of glaciation are derived from the underlying soft Great Plains rocks. Most of the soils in the north, formed in glacial deposits, are undulating to rolling and generally are better for cultivation than the rougher lands with residual soils to the south. In the valley bottoms most of the soils are formed from unconsolidated alluvial and glacial deposits and are productive for crops when irrigated.

Climate

The climate of most of Great Plains Montana is semiarid, with hot summers and cold winters. Average annual precipitation is scant, about 13 inches (330 mm); the plains are subject to cycles of drought followed by periods of unusually heavy rainfall and flooding. Total snowfall is light, though frost or freezing occurs more than 200 days of the year. The chinook, a warm winter wind that blows on the plains near the foot of the Rockies, periodically interrupts the bitter cold—January temperatures average in the upper 10s F (about −8 °C)—for which Montana is notorious.

In Rocky Mountain Montana there are several different climates arranged one above the other in elevational zones. The climate of the lowest zone—the dry valley bottoms—is similar to that in eastern Montana. The climates of the other zones become progressively cooler, wetter, and more snowy with higher elevation.

Plant and animal life

For the most part, Rocky Mountain Montana is forested, and Great Plains Montana is grassland. In the Rocky Mountains and on the mountain outliers the vegetation, like the climate, occurs in elevational zones. In the dry valley bottoms below the lower timberline are grassland, brushland, and open stands of trees called parklands. In the timbered belt on the mountainsides the vegetation is coniferous forest dominated by Douglas fir. The treeless crest lines above the upper timberline are made up of low alpine tundra vegetation, barren rock, and glaciers. In most of Great Plains Montana where the land is not cultivated, the vegetation is shortgrass and mixed-grass prairie. Along the base of the Rockies are foothill prairie grasslands. Many of the hilly areas on the plains are covered by prairie parklands.

Montana has an abundance of rare and imposing animal species, notably grizzly bears, Rocky Mountain goats, bighorn sheep, moose, and gray wolves (reintroduced in the 1990s). These animals live mainly in the mountains along with more common species, such as American elk, mule deer, black bears, mountain lions, bobcats, and forest grouse. There is a population of bison in National Bison Range Wildlife Refuge, in the northwestern part of the state, and bison from Yellowstone National Park migrate north into Montana during the winter. The grassland animals of Great Plains Montana and of the grassy western valleys include pronghorn, mule deer, coyotes, badgers, and plains grouse. Distributed nearly statewide along and near streams and lakes are white-tailed deer, beavers, muskrats, mink, bald eagles, ring-necked pheasant, ducks, geese, and swans. The Charles M. Russell National Wildlife Refuge on Fort Peck Lake (which is impounded by Fort Peck Dam) protects some endangered species.

Population composition

Most of the inhabitants of Montana today trace their ancestry to the countries of western, northern, and, to a lesser degree, eastern Europe—mainly Great Britain, Ireland, Germany, France, the Netherlands, the Scandinavian countries, northern Italy, Russia, Croatia, and Poland.

The one significant exception is the Native American population. Montana has seven Indian reservations, and Native Americans constitute more than one-tenth of the state’s total population. Nearly two-thirds of them live on the reservations and most of the rest in the cities near the reservations, notably Missoula, Great Falls, and Billings. African Americans make up just a tiny fraction of the Montana population. Asians have had a long historical presence in Montana, especially in the mining district around Butte, but are few in number today. The Hispanic population, once largely seasonal, grew substantially in the late 20th and early 21st centuries, though Hispanics still constitute only a small proportion of the state’s population.

About half the inhabitants of Montana are affiliated with organized religious groups. The Roman Catholic Church is the largest single denomination, but Protestantism as a whole has the greatest number of adherents; there are also smaller numbers of Mormons, Buddhists, followers of traditional Native American beliefs, Muslims, Jews, and others. Many of the Native Americans were nominally converted to Roman Catholicism by missionaries. The Northern Tier, along the Canadian border, was settled by German Hutterites; several dozen of their communities remain, and German is widely spoken within them.

Demographic trends

Montana’s population is somewhat older than the national average, largely because of the lack of professional opportunities for younger people and to the large number of retirees in the state. In the late 20th and early 21st centuries, the state experienced a greater population growth than the national average, particularly in the south-central and western regions; the growth was largely due to in-migration. During that period Montana attracted an increasing number of affluent out-of-staters who built second homes there.

Settlement patterns

The population of Montana is small, sparse, and unevenly distributed; slightly more than half is urban. In the two narrow-valley mountain areas, the population is aligned in thin strips along the valley bottoms, and towns are small. The broad-valley region has a heavy population by Montana standards, and some of the state’s major cities and large towns, including Missoula, Butte, Helena, Bozeman, Kalispell, Anaconda, and Livingston, are located in the irrigated districts on the dry valley floors.

In Great Plains Montana there are continuous bands of relatively dense population along the irrigated bottoms of the major incised valleys. All the cities and major towns, except Lewistown, are lined up like beads on a string along these strips. Along the Yellowstone River are Billings, the state’s largest city, as well as Miles City, Glendive, and Sidney; and along the Missouri River and its tributary, the Milk River, are Great Falls, Havre, and Glasgow. Population is moderately dense and fairly evenly spaced in the dryland grain areas, but it is sparse and uneven in the livestock-ranching areas.