A recently published book by Gerimino and others includes an informative chapter by Louis Provencher, Leonardo Frid, Christina Czembor and Jeffrey Morisette on applying state-and-transition simulation models to exotic brome-grasses in arid and semiarid ecosystems of the Western US. This chapter gives an overview of state-and-transition simulation models (STSMs) from a range management perspective and demonstrates STSM applications for determining efficient management resource allocation strategies; evaluating sources of uncertainty in models informed by expert opinion; and considering the potential consequences of climate change  on land management outcomes.