I will present a Bayesian hierarchical model for the joint spatial dynamics of a host-parasite system. The model was fitted to long-term data on the regional plague dynamics and metapopulation dynamics of the black-tailed prairie dog, a declining keystone of North American prairies. The rate of plague transmission between colonies increases with increasing precipitation while the rate of infection from unknown sources decreases in response to hot weather. The annual dispersal distance of plague is about 10 km and topographic relief reduces the transmission rate. Larger colonies are more likely to become infected, but colony area does not affect the infectiousness of colonies. The results suggests that prairie dog movements do not drive the spread of plague through the landscape. Instead, prairie dogs are useful sentinels of plague epizootics. Simulations suggest that the model can be used for predicting long-term colony and plague dynamics as well as for identifying which colonies are most likely to become infected in a specific year.