A gray Alaskan morning unfurls in Fairbanks as a coach eases north onto the Dalton Highway, headlights cutting through the low light and the landscape opening into scrubby tundra that seems to dare you to keep looking. The Trans-Alaska Pipeline runs alongside like a steel river, and as miles pass the trees thin, the ground levels out into vast, wind-sculpted plains. Guides punctuate the drive with stories; at the Arctic Circle sign they celebrate the invisible line where the sun refuses to set on summer solstice and refuses to rise on midwinter.