Roadside turnout - Photo taken from roadway turnout Gravel turnout with information sign. Text on the sign indicates this is the home range of the Forty Mile caribou herd. The Forty Mile caribou herd was once the largest caribou herd in Alaska and the Yukon and one of the largest in the world. The Forty Mile caribou herd ranged from the White Mountains north of Fairbanks to Whitehorse. In the 1920s it was estimated that the herd was 568,000 animals. Biologists now estimate the population to be about 46,000 caribou, (2003). Alaska Top of the World Highway The Alaska, Top of the World Highway, leads to Dawson City, Yukon Territory, Canada. This portion of the Top of the World Highway is an unpaved narrow winding with great untouched scenery.