The essential guide to Wyoming's national parks

Mountain peaks are reflected in a lake at Grand Teton National Park. Photo / 123RF

Wide open spaces, geysers, boiling mud pools, lofty mountain ranges and large populations of bison, wolves and moose lend this state's parks unusual grandeur

As the USA's National Park Service celebrates its centenary, we're profiling the wilderness areas it manages.

Today: The national parks of Wyoming . . .

Grand Teton National Park

"This is how mountains are supposed to look."
- President Theodore Roosevelt

The superlatives "awesome" and "amazing" have been diminished by overuse. But we still have "majestic." And there are still landscapes — including here — that merit that description.

Majestic might also apply to the creatures that populate the ground that surrounds the Teton peaks. Park inhabitants include bison, weighing in at as much as 900kg, and calliope hummingbirds, as light as two paper clips.

The tiny calliope breeds in the chilly mountain environments and is remarkable for being the smallest bird in the United States and Canada and the smallest long-distance avian migrant in the world, according to Cornell University.

The beauty that surrounds such creatures is, like them, both grand and subtle. They all play a role in the Greater Yellowstone Ecosystem, which encompasses this park, Yellowstone Park and portions of Wyoming, Montana and Idaho.

This vast network of flora, fauna and geology is a significant interconnected environment. Here, grass is essential for the soil and for the animals it feeds. Tickle grass and tufted hair grass, among others, tint the vistas with subtle hues.

The land here beside the city of Jackson Hole also fed early tribal inhabitants. Native Americans roasted camas bulbs, for example, in underground pits.

Grand Teton and the Teton Range. Photo / 123RF

Today Grand Teton, named for the main peak, feeds visitors' hunger for nature and recreation. Activities include mountaineering, hiking, backpacking, bicycling, fishing, boating, floating, skiing, snowshoeing and, of course, sightseeing.

Among the hiking trails is the Paintbrush and Cascade canyons' 29-kilometre loop. The Wilderness Society says this route offers "winning views" of the Cathedral Group, which are the tallest peaks in the Teton Range.

The panoramas here have attracted moviemakers. Grand Teton has served as a backdrop for parts of Django Unchained, Rocky IV and Shane.

Size: 310,044 acres

Founded: 1929

Attendance: 3,149,921 (2015)

Yellowstone National Park

"[It] is no more representative of America than is Disneyland."
- John Steinbeck, author, in 'Travels with Charley: In Search of America'

A herd of bison grazing in the sagebrush plains of the Lamar Valley in Yellowstone National Park. Photo / 123RF

This, the first US national park, in part owes its physical asset to the active volcano that lies beneath its surface, where the Park Service says there's enough magma to fill the Grand Canyon about 11 times.

Seismologist Robert B. Smith has described the park as "an active geologic laboratory — and the laboratory is alive."

That living landscape speaks through 10,000 hydrothermal features: hissing fumaroles (steam vents), spewing geysers and gurgling mud pots. Old Faithful geyser, the most well-known, erupts about 17 times a day.

The subterranean side of Yellowstone is what the Park Service has called a pressure cooker. Above ground, much of Yellowstone is a protected paradise. Its beauty became widely known when photographer William Henry Jackson documented the region for the US Geological and Geographical Survey of the Territories. His images helped inspire Congress to establish the park.

Yellowstone's geothermal origins are evident throughout the park. Photo / 123RF

Yellowstone is large, with 17 rivers, 290 waterfalls, five entrances, 4000 bison and acreage spanning portions of three states (96 percent in Wyoming, 3 percent in Montana and 1 percent in Idaho). It has the largest lake on the continent at a high elevation (2357 metres).

Yellowstone is home to the largest concentration of mammals in the lower 48. In addition to bison, those inhabitants include grizzly bears, wolves, lynxes, foxes, moose and elk.

Humans also have left their mark on this western range. It has 26 associated Native American tribes, 466 miles of roads (310 miles paved) and more than 900 historic buildings. Included among those vintage structures are Old Faithful Inn and the Lake Hotel, built in 1891, the oldest operating hotel in the park.

Also here is an unexpected category: "other life forms." That "other" is heat-loving bacteria, which create the ribbons of color in hot water.

As the Park Service explains, the green, brown and orange mats are cyanobacteria, which can thrive in waters as hot as 167 degrees. Here, the colours are visible in the Grand Prismatic Spring at Midway Geyser Basin. Grand Prismatic is the largest hot spring in the country and the third largest in the world.

In 1871, well before color photography could document the vibrant phenomenon, Ferdinand Hayden, leader of the US Geological Survey expedition, described the hot spring's "peculiar vividness and delicacy of color [from] nature's cunning skill."

Size: 2,219,791 acres

Founded: 1872

Attendance: 4,097,710 (2015)