Abstract Most studies of state/economy relationships focus on national and global institutions and minimize the importance of local, sub‐national institutions. This lack of attention to sub‐national states also characterizes most of the studies that examine the role of the state in the structure of agriculture. On the other hand, calls for a new type of sustainable agriculture argue that this type of economic system will be embedded in local political institutions. The nature of these local institutions, however, has gone largely unanalyzed. Through a comparative historical analysis of sub‐national state intervention in the regional economic structure of the U.S. dairy industry in the New Deal era, this analysis shows how state dairy policy has reflected sub‐national interest group politics surrounding food, agriculture, and rural land use. Sub‐national states responded to the agricultural crisis of the 1930s by spatially reorganizing agricultural resource use within their territories. The three states examined—New York, Wisconsin, and California—influenced the resource intensiveness of dairy agriculture by managing the spatially segmented boundaries that separated resource‐intensive and low‐resource dairy production systems.