The Terrestrial Environmental Observation Network (TEON) is intended to meet the need for asustainable environmental observing network for northern Alaska. TEON is organized aroundrepresentative focal watersheds (Figure 1). TEON will collect, distribute, and synthesize long-termobservational data needed to detect and forecast effects of a changing climate, hydrology, andpermafrost regime on wildlife, habitat, and infrastructure in northern Alaska.