Our ancestors—and ourselves— have always lived within the shadow of mountains. The story of our enduring relationship with the mountains and plateaus of the world begins more than one million years ago at the margins of the Rift Valley in Ethiopia. There, at sites at elevations ranging from 2000-2400 m, our hominin ancestors obtained obsidian from outcrops and most likely foraged for food. Over the next million years, as our ancestors moved out of Africa into new habitats, they found both challenges and refuges in the mountain ranges they encountered. It has long been believed that the peopling of these high places came late in our evolutionary past—certainly within the past 40,000 years, but recently discovered evidence from Tibet challenges this assumption. In this presentation, I examine the biological, genetic, and archaeological evidence from around the world that provides a context for understanding how some of us became highlanders from our lowland origins, and when our species, or perhaps our ancestors, moved into these high places to live permanently.