Every day, dozens of trucks make two roundtrips apiece hauling hay from Washington’s Kittitas County to the Ports of Tacoma and Seattle, where the containerized feed will be loaded onto ships bound for Japan, China, and still-more-distant markets. The rapid growth of the export hay industry helps explain Washington’s membership in a group of just five states having trade surpluses with both China and Japan in 2011. In fact, the industry is robust in the interior not only of Washington but also Oregon, California, and even farther inland. In this article, the growth and significance of the hay industry in the U.S. West, and especially Kittitas County, are assessed. Drawing on interviews with hay growers and export-processors, the physical, economic, technological, and social factors that have favored the industry’s emergence are examined. While the hay industry is fundamentally rooted in the region’s seemingly natural advantages of soils and climate, a variety of forces at the global, regional, and local scales have augmented those benefits and propelled the industry’s rise. The article ends by looking toward the future opportunities and constraints the region’s hay industry faces—especially the growth of emerging markets and the concerns about the adequacy of water supplies, respectively.