The weatherworn sign on the outskirts of Ushuaia proudly reads "Bienvenidos a la Ciudad mas austral del Mundo" - Welcome to the Southernmost City in the World. The tires of our heavily laden GS bikes bite into the freshly fallen snow as we excitedly pull on past.

Summer was running out of gas. Yellow leaves fell gently, and autumn nipped at the air when we left behind the vineyards and fruit plantations north of Santiago on our trip to Mendoza, in Argentina. Like ghost riders, it felt as if we were heading straight into the sky.

The view from the plane was breathtaking: a seemingly infinite range of sharp, snowy summits stretched toward the earth's curve, among them the magnificence of Aconcagua, the highest peak in the Americas. Farther east, the land abruptly flattens out, revealing the vast, fertile expanses of the pampas, the lush green pastures that fatten untold herds of Argentine beef.