Chances are, you haven’t heard of Virgil Carrell. But if you’ve spent any time at all on America’s highways, his work is as familiar as McDonald’s golden arches. Although Carrell’s achievements ranged widely, the U.S. Forest Service’s iconic signs became his legacy they’ve endured, unchanged, for six decades. Carrell was born to railroad workers who spent their lives in remote parts of the Pacific Northwest, so it isn’t surprising that he earned a degree in forestry. During his long career with the Forest Service, he raised his own family in similar conditions.