Prolonged drought in the Southern Great Plains of the USA in recent years has raised concerns about vulnerability of beef cattle grazing systems under adverse climate change. To help address the economic viability of beef grazing operations in the Southern Great Plains, this paper provides an economic assessment of beef grazing systems under baseline and prolonged drought situations comparable to the 2011 drought in this region. A coupled economic and environmental modeling system was used to determine the impacts of the prolonged drought scenario on the net incomes of beef grazing systems. The results of the model simulations support the conclusion that prolonged drought of the extent witnessed in recent years would be financially detrimental to beef grazing operations, unless viable mitigation measures are implemented. Beef grazing operations are projected to lose at least a third and in some cases close to half of net incomes when faced with prolonged drought weather patterns.