The area around the confluence of the Silverthrone and Klinaklini glaciers in southwestern British Columbia provides a glimpse into how the terrain traveled by Native Americans in Pleistocene times may have appeared.
David J. Meltzer/Science
A Sandhill Crane flies in at sunset to roost for the night in the wetlands of the Monte Vista Wildlife Refuge in Colorado. Migrating along the same route they've followed for thousands of years, about 25,000 Greater Sandhill Cranes pass through the San Luis Valley in late winter every year.
Doug Pensinger/Getty Images