Hog production in 2004 was characterized by wide variation in the types, sizes, and economic performance of operations. Operations specializing in a single production phase generated more than three times the product value, on average, of those using the traditional farrow-to-finish approach. Low-cost operations tended to be larger, located in the Heartland, and operated by farmers whose primary occupation was farming. Small and medium operations far outnumbered large and very large operations, but large and very large operations accounted for most of the production. Average production costs declined as the size of the hog operation increased, a result of reduced capital costs and more efficient input use. Hog production was highly concentrated in the Heartland, but the largest operations were specialized hog finishing units in the Southern Seaboard.