Rock art - etched in blood-red lines into granite cliffs, boulders, and caves - appears as beguiling, graffiti-like abstraction. What are these signs? The petroglyphs and red-ochre pictographs found across Nlaka'pamux territory in present-day British Columbia and Washington State are far more than a collection of ancient motifs. Signs of the Time explores the historical and cultural reasons for making rock art. Chris Arnett draws on extensive archival research and decades of work with Elders and other Nlaka'pamux community members, their oral histories and oral tradition, to document the variability and similarity of practices. Rock art was and is a form of communication between the spirit and physical worlds, a way to pass information to later generations, and a powerful protection against challenges to a people, land, and culture. Nlaka'pamux have used such culturally prescribed means to forestall external threats to their lifeways from as early as the sixteenth century - when they were aware of incipient European encroachment - until well into the twentieth. As this important work attests, rock art remains a signature of resilience and resistance to colonization among Nlaka'pamux today.