During the Middle Horizon (A.D. 540–900) the Wari of the central highlands Ayacucho region expanded their control into many parts of the Andes. While different motives have been cited for Wari state expansion, we suggest that a severe and prolonged drought during the sixth century may have played a significant role. We posit that the Wari responded to this environmental crisis not only by seeking practical solutions, such as securing productive land outside the heartland, but also by implementing religious practices intended to cosmologically restore fertility to drought-stricken areas and validate acquisition of arable land in foreign territories. Using a model of Inka ideology developed by Peter Gose, we propose that a strong religious complex involving ancestor worship, huacas, and the cosmological control of water led the Wari to seek out and control locations where water could be drawn from supernatural sources. The presence of large bodies of water near major Wari administrative sites as well as other natural phenomena, particularly certain mountains, rock formations, and large stones, and site offerings of Spondylus, copper, and stone figurines support this model. A sacred Wari landscape is thus seen as complementary to the established political landscape and providing a supernatural justification.