At 3,570 metres the pass is among the highest paved routes in the state, linking Georgetown and Grant through forest, willow flats and finally open tundra. The summit of Bierstadt, at about 4,285 metres, is named for the painter Albert Bierstadt, who visited in 1863 and made the mountains of the West famous with his enormous luminous canvases. A rider stopping at a pull-off near the top can see a good deal of what he saw.
The view is of the Mount Evans Wilderness, a high basin of lakes, boulder fields and spruce. In late summer the willows in the valley below the pass turn gold and orange, and moose, which were introduced to Colorado in the 1970s, feed in the marshy ground. Ptarmigan, small grouse that turn white in winter, hide among the rocks, and mountain goats and bighorn sheep browse the cliffs of Mount Evans. The alpine tundra has a short, bright season of tiny flowers in July, and the air smells of spruce and cold stone.
The ride up from Georgetown, a restored silver-mining town of about a thousand people, is a series of tight switchbacks and steady climbs, with views back over the valley and the old railway loop, which was once one of the engineering marvels of the Rockies. The road is narrow, with steep drops on the outside, and the surface can be broken by frost. Traffic is heavy on summer weekends and during the aspen colour in late September, when cars crawl up the bends. Snow can close the road for long stretches, and ice can form any month of the year.
Fuel is not available at the pass. The best places to fill the tank are Georgetown or Idaho Springs, near the interstate, and anything beyond that is a bonus. The altitude saps the engine's power, and riders should be wary of headaches, nausea and shortness of breath. Bring warm layers and rain gear, since afternoon thunderstorms are common.
Go in the morning, when the air is clear and the light is crisp, and leave the high ground before the clouds begin to build.