The Yellowstone River starts its great journey

Just off the Continental Divide, deep in Wyoming's Absaroka Range and Teton Wilderness, Younts Peak brushes thin air at 12,156 feet. When the melt season arrives, snowfields in a cirque high up on the massif’s north face and other flanks are adorned with countless rivulets. Trickling off the snow, they weave in the mountain’s tundra, forming into small creeks as they gather in the denser vegetation below and provide the initial waters for the North and South forks of the Yellowstone River. Beneath Younts’ west wall, the two branches unite to power the surge of the largest undammed, free-running river in America as it commences its 670-mile odyssey to meet the Missouri beyond Sidney, Mont. And what a journey it makes!

From its spawning grounds 28 air miles below Yellowstone National Park’s southeast corner, the fabled river enters a narrow deep canyon fighting its way down a boulder-strewn course. For about 10 miles the newly formed river passes through a forest of pine, spruce and fir fitted with small meadows and willow flats. The 1988 fires that burned a great deal of acreage in Yellowstone National Park also touched this corner of the Teton Wilderness, and as a result some new aspen growth is being observed. The conifer mix is changing, and lodgepole is coming back in places, while exhibits of wildflowers — including arnica and fireweed — are sprouting up under the burnt snags.

Numerous unnamed streams and waterfalls tumble off the Continental Divide to the west and from Thunder Mountain and volcanic cliffs on the east. Industrious beavers have created ponds in many places. The rough Continental Divide Trail follows the river on its north and east side, with many small but easy creek crossings. The exception is the braided and gravelly Castle Creek where it pours over landslide and flood debris. Fording Castle on horseback is easy, but a foot traveler will get wet.

Here the river connects with some of the nation’s finest wilderness landscape — beautiful, untamed and gaining its wild soul. Far from any road, this is the gorge of the Upper Yellowstone.

Near Castle Creek the Yellowstone departs its canyon confines and embarks on a torturous meander through marshy river bottoms of the 21-mile Yellowstone Meadows and Thorofare Valley. These wetlands extend from 1 to 2 miles across and the river with its islands, channels and deep pools up to 160 feet wide in places. Lush meadows of high grass and dense willows provide prime moose habitat, as well as a summer home for the Northern Yellowstone and Jackson Hole elk herds. Cutthroat trout move upriver to spawn here in early summer, attracting the king of the wilderness: the silvertip grizzly bear. Other wildlife, including bison, eagles, bighorn sheep, cougars and deer are plentiful. Canada geese and sandhill cranes call out early in the morning throughout the summer, and a pack of the Yellowstone wolves has taken up territory here.

The trail coming from the river’s headwaters and Marston Pass on the Continental Divide intersects with several other routes near Bridger Lake and Thorofare Creek. Here the Thorofare Trail takes over and heads toward Yellowstone Lake, skirting and passing through the meadow’s east perimeter. Fording some of the peripheral streams, especially Thorofare Creek, can be tricky business. The water in these wildlands is swift, deep and cold. High runoff and lasting snowbanks make much of it impassable until mid-July ... and this is just part of the great wilderness experience this first segment of the Yellowstone River offers.