In the paper the authors are focused on local and trans-border migration processes in Northern Dalmatia and their influence on the economic and demographic development of the Vrana feudal estate during the 17th and 18th century. The research was based on the complex and qualitative analysis of demographic, economical, confessional and cartographic archival sources, followed by the correlation of existing secondary literature research (desk-study analysis). The primary scientific goal was to determine how the land reclamation and corresponding protomodern migrations, which had occurred prior the statistical period of migration registration, have changed and influenced further economic and environmental development of this particular hinterland of the Dalmatian area. The change of the lowland marshy borderlands was investigated within the frames of its physical ambience, geo-strategic position, and its communication, commercial and migratory potential, within the interdisciplinary framework and discourse of ecohistory and environmental studies methodology and approach. In addition, this paper tends to discuss whether the Borelli family's private venture of investing in land reclamation was an economic success or rather an adventurous experiment since they failed to keep the immigrants colonized from Bukovica in permanent settlements. After getting the Vrana estate as a feudal possession in 1752, these Italian family members undertook a huge action of marshland and land reclamation in order to re-evaluate and redefine land use in the area that was once a prosperous Roman barn field, which provided food for a much larger population. Consequently, these newly gained lands were used by the state, along with some other tax and administrative benefits, to attract agrarian labour force. After drying the Vrana moors and marshes, damp soil improved in quality and the excess water was taken away, especially after the trenching of main and collateral ditches and a huge canal of Prosika, which connected the Lake Vrana with the Adriatic Sea, and the immigration has continued. Considering the motives of these protomodern migrations as an interplay of intertwined migration factors, some typology of the most common patterns of spatial mobility has been discovered, including the patterns, shapes, directions and intensity of these migration lines. They included not only the war and post-war emigration from the estate, but also the immigration of Morlachs from the hilly area of Bukovica or even across the Ottoman borders in the hinterland, and transmigration, as well as family-related local migration, and seasonal shepherd (transhumant) migration (circulation) in the area. A specific “transborder” migration was a type of colonized compelled immigration of peasants from northern Italy (Furlania) to Northern (Venetian) Dalmatia as a working contingent of people, along with rare and occasional migrants of Italian nobility who conducted, directed and financed the Vrana reclamation projects (e.g. the Borelli from Bologna). The case study of migration network in the village of Tinj, besides the majority of settlers from the north-western area of Bukovica, has also revealed the immigrants from Primorje and even from the islands of Zadar archipelago coming to the Vrana estate. Some of them also helped in the drainage projects. New contingents of “healthy highlander Morlachs” from Bukovica were continuously invited, since they were perceived as more resistant to marshland fevers and likely to endure malaria-like diseases, which had significantly diminished the economic productivity and demographic potential of population in lowland areas. This local migration of Morlachs resulted in their engagement in reclamation as an additional task to their existing role in defense of Acquisto Nuovo and Acquisto Nuovissimo (Venetian hinterland) against eventual Ottoman Reconquista. During the period of destructive Anti-Ottoman wars in Kotari, the geostrategic relevance of this particular feudal estate's borderland position on the edges of various states, economic systems and cultures was of the utmost importance. On the other hand, its liminal position as the Venetian overseas territory minimized the central state support and care in various kinds of perils. Hence, colonized immigration did not have ecological character although new settlers changed the landscape of Kotari. New and intensive agricultural (farmer) exploitation failed to upgrade economy since the prevailing sheep-breeding in highly fertile land represented the economic irrational land use. Demographic and economic development reflected the devastating results of anti-Ottoman early modern wars, followed by the environmental requirements and pressure of the Venetians. Getting in between the environmental interventions aiming to reach higher economic standards, the feudal estate happened to be radically changed by the reclamation. It was, for the first time since the Roman era, an extraordinary intervention into natural balance of the lowland ecosystem. The results of these early modern collisions of economic and environmental interests in Vrana in the short period significantly differed in quality and direction of its development in comparison to the long-term perspective. On the one hand, especially in the middle and long-term perspective, it showed elements of economic and demographic success, with a reasonable potential to fully reshape the demographic potential of the area. Quite contrary, the short time scale was, if not a complete failure, then at least an uncertain and adventurous experiment. In spite of that qualification, Francesco Borelli’s reclamation of marshlands was a hydro-technical step forward, totally in accordance to similar European intellectual (physiocratic) movements and projects, reflecting the spread of comparable ideas to the eastern corners of eastern Adriatic territories under European rulers. However, the Borelli family also encountered serious obstacles in implementing innovative plans, such as continued political and military insecurity on the borderland(s), including also the Ottoman part (serhat). Besides the fiscal and other privileges that were promised to Morlachs in order to attract them to the deserted land by the former owners, Borelli’s innovative and economic capacities were further jeopardized by the lack of solid political (and organizational) support of Venetian administration. They even did not succeed in settling the colonized immigrant population more permanently into the nine villages of the Vrana estate, partly due to additional irrigation work Morlachs had to complete, but also due to disadvantageous demographic threat represented by the unknown medical dangers such as malarial fevers. Since these phenomena were unknown and undiagnosed (prior to the mid-19th century) the adequate treatment or prevention could not be applied. In spite of all unfavourable factors or even failure to decrease circulation of local population in the area, these projects can be defined as revolutionary inventive for the 18th century, especially for Dalmatian periphery. Among other ecological results, human intervention into drainage of devastated and abandoned water sources and channels led to formation of highly anthropogenically shaped landscape, which was crucially dependent on constant cultivation and protection. Moreover, expensive reclamation projects were not fully and properly exploited, since the Ottoman presence in the vicinity and total insecurity prevented and even repulsed Morlach shepherds from changing their low profit shepherd economy to high profit intensive agricultural land use. Such a misbalance of economic and environmental interests tended to reverse Borelli’s efforts and new economic exploitation kept the economy on unsustainable levels, detaining the irrational management of energy, resources and land. On the other hand, the improved soil and drained land allowed a slow increase of crop each year, ensuring higher self-provision of the local population. Demographic growth was gradual and endangered by malarial fevers. They significantly reduced the number of people, especially children, but also limited economic productivity of those who survived. However, life standard increased based also on the extension of arable lands. Intensive agricultural production with new cultures increased the productivity level. The collision of economic and environmental interests resulted especially in long-term improvements of the main trends since the early modern economy was highly dependent on natural cycles and not based on intensive agriculture, but rather on extensive transhumant cattle breeding, which could not effectively correspond to huge human/material investments into land reclamation, especially in a short time span. Gradually, the land improvement opened new economic possibilities, being fully exploited after the extending and widening of the Prosika canal, which had been finished during the Austrian rule in the 19th century. The failure of the Borelli’s project reflected in the abandoning of the works and bankruptcy of the count Francesco, but the reclamation results turned to be the base for economic/demographic achievements in later centuries. The extinction of malarial fevers and the episodes of other diseases were followed by founding of huge farms in the 20th century. By providing a significant areal of new fertile land which was safe from a sanitary perspective, the local population got the possibility to permanently settle the lowland Vrana villages and improve disadvantageous demographic trends. By comparing incomparable, it is obvious that contrary to huge waist of energy and resources (e.g. of water and fossil fuels) in modern Western societies, a low level of agricultural production in Vrana and high dependence on natural principles have been ecologically and environmentally sustainable, especially in long-term perspective. The same collision of nature (environment) and economy today usually ends in short-term economic results and total neglecting of any other interest. Therefore, Vrana's reclamation represented, on the one hand, the abduction of moors and marshes, and their return to man, but on the other hand, an achievement of regained balance between economy and ecology. Such an equilibrium, as it was accomplished in the 18th century by the Vrana reclamation, can be rarely met even today.