Watch Modern Marvels Season 10 Episode 6 Online

Today, vacationers travel from British Columbia north through the Yukon Pass on their way to Fairbanks, Alaska, thanks to one 2-lane roadway, the 1,522-mile long Alaska Highway. A bit treacherous in spots and best driven in the few summer months the region provides, it's an unrivaled engineering feat that took 11,000 soldiers, nearly 4,000 of them black, only eight months to build! Travel back to 1942 as they bulldoze their way into history while connecting the Lower 48 to the Alaskan Territory.