In Montana, the earth seems to have turned itself inside out, its hot insides leaking into hot springs and geysers, its bony spine thrust right through the skin of the continent to form the Continental Divide, making it a geologist's dream. And to a biologist it's heaven, one of the last regions in the United States with enough open space for animals like elk and grizzly bears to roam free.

Plains, basin, and range alternate in this high-altitude environment that is in large part defined by its extremes of weather and climate. These changing landscapes make Montana one of the best vacation spots in the country for travelers who like their scenery dynamic and dramatic.

The western side of both states is mountainous, dragging moisture from the clouds moving west to east and storing it in snowpack and alpine lakes. Because the ridge of the Rockies wrings moisture from the atmosphere, you find deeper, denser forest extending far to the west, while on the east side, the lodgepole pine, spruce, and fir forests give way to the Great Plains, a vast, flat land characterized by sagebrush, native grasses, and cottonwood-lined river bottoms.

But a lot of the landscape dates back more than 100 million years to when the collision of tectonic plates buckled the earth's crust and thrust these mountains upward. Later, glaciers (of which some vestiges remain) carved the canyons. The tallest peaks in Wyoming are located within the Wind River Range, which rises from the high plains of South Pass and runs northwest to the Yellowstone Plateau. Nine of the peaks in the Winds have elevations over 13,000 feet; Gannett Peak, at 13,785 feet, is the highest in the state. Several other mountain ranges are found to the south of Yellowstone -- including the Absarokas and the stunning Tetons -- and from Yellowstone north into Montana run other dramatic ranges, including the Gallatin, Madison, Mission, Bitterroot, Cabinet, and Beartooth, where you'll find Montana's highest point, Granite Peak, at 12,799 feet.

The Continental Divide enters Montana from Canada and traces a snaking path through the two states. Both Montana and Wyoming have rivers flowing west to the Pacific and east to the Atlantic.

Here you'll also find the headwaters of major river systems -- the Flathead and Clark Fork heading west into the Columbia from Montana, along with the Snake from Wyoming; the Yellowstone, North Platte, and Madison joining the Missouri bound east; and the Green from Wyoming emptying into the Colorado heading south. These rivers are the lifeblood of the region, supplying irrigation, fisheries, and power from dams. Montana also boasts the country's largest freshwater body of water west of the Mississippi River: Flathead Lake. Yellowstone and Jackson lakes are Wyoming's two largest natural bodies of water.

Montana is the greener of these two states, with more abundant alpine wilderness and bigger rivers. Wyoming, however, has been dealt a more interesting hand of natural wonders: waterfalls, geysers, and other geothermal oddities at Yellowstone; as well as the natural landmark of clustered rock columns that rise more than 1,280 feet above the surrounding plains at Devils Tower National Monument, near the state's Black Hills region of the northeast. At Wyoming's Red Desert, south of Lander, the Continental Divide splits to form an enclosed basin where no water can escape, and nearby you find Fossil Butte National Monument, an archaeological treasure chest of fossilized fish and ancient miniature horses.

The states are characterized by long, cold winters and short summers of hot days and chilly nights. Temperature ranges are dramatic, and are largely dependent on elevation. Except along the far western edge of Montana, precipitation here is less than 30 inches a year. It's considerably less as you journey east and south. But the snowpack in the high mountains -- more than 300 inches accumulate in some areas -- melts through the summer and keeps the rivers running.

Planning a trip to the area can be done in several ways. Those interested in a particular activity, such as hiking, might choose two or three locations and divide their time among them. Conversely, one could first select a destination, such as one of the national parks or an Old West town, and then determine the activities to be pursued there.

Glacier Country & the Northwest Corner -- This includes Glacier National Park, the Flathead Valley and northwest corner of the state, and Missoula, one of Montana's three largest cities. The national park draws millions of visitors annually who come to see its soaring peaks, varied wildlife, and innumerable lakes and streams. The Going-to-the-Sun Road, a 50-mile scenic highway that cuts through the heart of the park from southwest to northeast, makes Glacier surprisingly accessible. Elsewhere in the region, the increasingly popular Big Mountain draws downhill skiers, and Flathead Lake is a magnet because of its excellent watersports and quality golf courses. One of the fastest-growing areas in the state, the Flathead Valley shelters an interesting mix of residents: Farmers and loggers share ski lifts and trout streams with transplanted urbanites and big-bucks entrepreneurs, all looking for their slice of paradise. On the southern edge of the region is Missoula, a vigorous college town with good restaurants, interesting shops, and bits of Montana history.

Southwestern Montana -- This area is extremely diversified. Helena, a town centered on arts and politics (though not necessarily in that order), has a beautiful historic district filled with classic architecture and access to tremendous fishing on the Missouri River. Butte, on the other hand, is working hard to overcome the decay caused by the exploitation, then abandonment, of its mines. Other areas in this part of the state are full of lore. Vigilantes and corrupt sheriffs dominate the stories of the "ghost towns" of Virginia City and Nevada City, both of which are kept alive today by tourists seeking a realistic glimpse into America's past, and Bannack, an abandoned ghost town that's now a state park.

Missouri River Country -- One of the least populated areas in the state, this region stretches from the mountains to the eastern border and is distinguished by prairies that roll along for hundreds of miles. Great Falls, the region's largest city, is a mecca for those interested in the story of famed explorers Lewis and Clark. U.S. 2, or the Hi-Line -- that long stretch of pavement that runs across the northern part of the state -- cuts by a series of farms and ranches that perpetuate the homesteader life. New farming equipment and satellite dishes are just modern polish on an old tune.

South-Central Montana (Yellowstone Country) -- Though this region is almost a twin of the northwest part of the state in many ways -- a nearby national park, renowned ski resorts, a university, lots of tourists -- it has a unique personality. The city of Bozeman is home to Montana State University and a vibrant downtown. Anglers come from all over the world to fish these blue-ribbon trout streams, but the main attraction in this part of the state is Yellowstone National Park. Still, even the valleys that lead to it -- the Madison, Gallatin, and Paradise -- are spectacular destinations themselves.

Eastern Montana -- The geography in this part of Montana is similar to its neighboring region to the north, but there are more people and more things to do here. Billings is the supply center for eastern Montana and northern Wyoming. It's easily the largest city in Montana and has prospered, even without the helpful hand of tourism that the western side of the state has seen. The Bighorn Canyon and the Yellowtail Dam draw their share of visitors, especially hunters and anglers, but this region's main attraction is Little Bighorn Battlefield, where Gen. George Armstrong Custer led the 7th Cavalry to defeat at the hands of the Sioux and the Northern Cheyenne.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.