This paper evaluates two recently implemented strategies to control land use conflict and overgrazing in Kajiado district of southern Kenya, stressing the importance of analyzing attempts to alter traditional pastoralist production systems in terms of the "complex ethno-ecological mosaic in which political power allocates access to strategic resources". A situation, structure, performance paradigm is applied to the problem. Factors central to the situation which underlie the issue of overgrazing are grounded in the ecological and historical context. Highly unpredictable rainfall, repeated drought, and an increasingly constricted resource base form the primary constraints of the Masai production system. In response, complex cultural adaptations and herd management strategies have evolved to provide maximum security and support for the institution of the family. It is these social factors which must be kept in mind as the evaluation of intervention strategies proceeds. Two intervention strategies designed to address the issue of overstocking from slightly different perspectives are described in detail and then evaluated in terms of their likely performance outcomes. These strategies are land adjudication into group ranches, and the payment of Wildlife Utilization Fees to group ranches bordering on the national parks. For a number of reasons; especially those related to property rights, and the costs of obtaining information, reaching agreement, and enforcing decisions; it appears unlikely that either strategy will be very effective in changing herd management practices such as mobility or the stocking of large numbers.