Why, when, and how people developed highly specialized marine economies remains the focus of considerable anthropological research. Study of maritime adaptations at high latitudes has potential to contribute to this debate because low biodiversity and increased resource seasonality at high latitudes made reliance on marine resources particularly risky. New research at the Cape Krusenstern site complex, located in northwest Alaska, offers a rare opportunity to study the evolution of maritime adaptations across the environmentally dynamic mid-to-late Holocene Arctic. Large-scale and systematic survey of this important site complex was undertaken to address questions about the timing and character of early Arctic coastal lifeways. Our research yielded direct dates of 4200 years ago for the oldest occupation of the site complex and identified several new sites dating to between 4200 and 2000 years ago. Results support the existing settlement model, pointing to increased sedentism and local population only after 2000 years ago. New data, however, indicate local population was much higher than previously established and that coastal occupation was sustained over long periods of time despite considerable mid-to-late Holocene paleoenvironmental variability. Together, these findings raise new questions about the evolution of maritime adaptations at high latitudes.