4. Forest Canyon Overlook
Beyond Rainbow Curve, the drive skirts stunted pines that have been contorted into odd shapes by the relentless wind. Scattered among them are “banner trees,” whose limbs grow like flags on the leeward side of their trunks. As the road continues to ascend, even the trees disappear, yielding to tundra: a world of grasses and wildflowers only inches high. Although the growing season is brief (just 6 to 12 weeks in midsummer), it manages to produce a glittering display of blooms — sky pilot, clover, moss campion, phlox — in an otherwise bleak alpine landscape.
From the overlook high above Forest Canyon, the distinctive U shape of this glacial valley is quite evident, once filled hundreds of feet deep with moving ice. Echoing the glacial era are the Gorge Lakes; cupped in ice-sculpted bowls called cirques on the canyon’s far wall, they remain frozen until well into summer.
5. Tundra Nature Trail
For a close-up look at tundra vegetation, stop at Rock Cut Overlook and walk the half-mile Tundra Nature Trail. Here bucktoothed marmots sun themselves on rocks or scamper across the ground. Less at home are human visitors, who often gasp at the slightest exertion in the thin air at 12,000 feet. But inhospitable as this setting may seem in the warmer months, the scene in winter is truly forbidding: the wind can top 200 miles an hour, the temperature plunges to -60° Fahrenheit, and snowdrifts can reach as much as 30 feet deep.
6. Lava Cliffs
The “lava” here is really volcanic ash deposited 26 million years ago and compacted under heat and pressure into the rock called tuff. Glaciers, the architects of the Rockies, later stripped away overlying material to expose this remnant of the area’s volcanic past.
Within the next mile the road arrives at its highest point: 12,183 feet above sea level. Far to the west rise mountains that inspired one of the park’s most poetic names; because snowfields on their upper slopes remain visible all year, the white-patched peaks are called the Never Summer Mountains.
7. Alpine Visitor Center
Barren though it may seem, tundra harbors a fascinating array of life, from seldom-seen pocket gophers that tunnel just below the ground to perky little rosy finches that pluck frozen insects off glacial ice. Exhibits at the Alpine visitor center highlight these and other forms of wildlife in this treeless world, comprising nearly a third of the park.
Trail Ridge Road now descends to Medicine Bow Curve, a hairpin turn overlooking the Medicine Bow Mountains. Far below lies the Cache la Poudre River, named by French trappers who once stored their gunpowder nearby.
8. Milner Pass
Back below the tree line, a one-mile trail leaves the road and heads uphill to the Crater, one of the park’s best spots for sighting bighorn sheep. Males use their big curved horns to battle for dominance; when two rams butt heads, the crack echoes through the mountains like a rifle shot.
Just after passing Poudre Lake, whose waters eventually drain into the Mississippi River, the drive crosses the Continental Divide at Milner Pass. Beyond this point raindrops from a summer shower join the Colorado River and pass through the Grand Canyon before flowing into the Gulf of California.