Alaska

The Route: Riding 12 to 23 days along what may be the only paved highway on the continent where wolves, grizzlies, and bald eagles take the place of billboards, and hot springs, azure lakes, and snowcapped peaks stand in for rest areas.

When to go: June through August

Difficulty: Difficult

Travel advisory: How much can you take? Alaskan bicycle Adventures leads you 759 miles in 12 days from Juneau to Anchorage, whole Cyclevents’ 23-day route stretches an epic 1,421 miles from Delta Junction, Alaska, to Dawson Creek, British Columbia — Alaska Highway Mile Zero.

High/low points:

• Carbo-loading on elk spaetzle and apfelkuchen at The Raven, an unlikely oasis of superb german cuisine in Haines Junction.
• Discovering firsthand how the Hills of Significance, north of Haines, got their name — courtesy of the lactic acid pooling in your quads.