Within the framework of the “march to the sea” policy (the colonization ofMexico’s tropical regions), from the early 1950s extensive areas in the South of the State of Veracruz were integrated in the movement towards agro-pastoral colonization. The article aims to show how in half a century, the economic transformations led by the Mexican State contributed to shaping the land structures in the specific context of a pioneer front. The analysis is based on inquiries conducted in the municipality of Playa Vicente on colonies (a particular type of land structure resulting from the land subsidies policies made within the framework of the Mexican agrarian reform) and on a close examination of the agrarian archives. The internal dynamics of the colonies are studied alongside other aspects of analysis. Two of these received special attention : the influence of public intervention measures, in particular the role of access to credit in the 1970s and 1980s, then the disengagement of the Mexican State ; and regional-scale relations through analysis of the economic and social connections with the nearby spaces dominated by private property (pineapple production in Isla municipality ; stock-breeders in the rest of the municipality of Playa Vicente). The economic dynamics shed light on the land relations at work, with a dominant tendency towards the reproduction of disparities.