In Europe, mountain livestock farming systems fall within the scope of the agro-ecological transition due largely to animals grazing on spontaneous vegetation. Recently, the development of organic farming production has become noticeable and has contributed to changes in production systems organization. In the context of a strong sociotechnical system, around dairy sheep production, in the “Grands Causses” region in southern France, we investigate whether this development is a means of fostering the agro-ecological transition. We interviewed seventeen farmers chosen to capture changes in breeding practices under effects due to sociotechnical system. We describe their conversion to organic farming using the processual analysis framework, studying the changes in their practices over time with regard to the sociotechnical system. In the early 2000s, some farmers entered the first pathway to organic conversion, while milk sales under organic signs were not possible because the local collection network was insufficient and the network was not near their farm. Then, in 2005, a second pathway to organic conversion emerged with farmers looking to increase their free time and their revenue, which requires increasing milk production (volume) and recruiting a new collaborator. These farmers chose to supply their organic milk with a price premium to dairies operating outside the Roquefort interprofessional organization, which at that time had restricted volumes by “quotas.” A third pathway to conversion was developed in 2014, following the abolition of the “quotas,” and it drew producers who were looking for a niche to secure the price of their milk; these producers were encouraged by the future buyers of their farms who wanted to continue with organic farming. In the three pathways, the farmers stopped using chemical inputs, replacing them with other practices and showing that organic farming permits certain agroecology principles, such as closing nutrient cycles. To sell milk with premium price due to organic products, some of the farmers changed the seasonality of production (April to October) and increased the productivity of ewes (liter/ewe), contributing to a reduction or abandonment in rangeland grazing. However, not all the farmers in our sample opted for these strategies, proving that organic farms are very diverse. This questions the choice of organic agriculture as a means of upholding all the principles of the agro-ecological transition and shows the importance of the sociotechnical system, specifically the organization of downstream sector and agricultural extension actors to promote it.