A splendid highway connects Alaska to South America, cutting through Canada and the United States alongside the Rocky Mountains, the Central American republics through deserts and forests, and the southern ones along the Andean chain. This documentary was made following the road from the Yukon valley to Mexico; the author paid particular attention to capturing the prodigious variety of landscapes and the most spectacular aspects of ethnography and customs. From the glaciers of subpolar lands to Aztec monuments, there is a continuous changing of colors and environmental subjects, counterpointed by multiform human activity.