1st movement - "Orogenies" or "mountain building," musically depicts the upheaval and birth of western North America's crust, seen today in such places as Royal Gorge.
2nd movement - "Rush!" is a fast and furious exploration of human history in relation to the geology of the American West, particularly the gold rushes of the 19th century.
3rd movement - "Requiems" returns to a slower and quieter pace, harkening back to the formation of fossil fuels in ancient oceans and coastal swamps.
4th movement - "Majesties" is the climax of the piece, defined by the iconic formations of the modern Rocky Mountains.