The methodology applied during 12 years in a cattle breeding herd in northwestern Argentina, located in the pedemontane forest of the Yungas, north of Salta, is described. The applied methodology allowed the evolution and productive growth, starting from a system with traditional management and low productive indexes, to a stabilized and efficient herd, with outstanding achievements in pregnancy and weaning indexes, and increase in weaning weight, well above the average of the region. The improvements obtained were based on the adequate intervention of sanitary-productive problems, planning, and progressive application of Fixed-Time Insemination and Early Weaning, improving reproductive management and incorporating genetics. The growth of the stock with its own rebreeding was favored, maintaining a closed herd. The application and intensity of the proposed methodology, together with qualified rural personnel highly experienced in cattle management in wild forests, allowed the growth of 110% in the stock of cows with an average pregnancy rate of 91%, and an average weaning rate of 78% in the last 8 years, with an average increase of 30 kgs/calf at weaning.