This thesis explores the environmental choices and adaptive strategies of the Late Tuniit (Dorset) at the SiFi-4 site, located in Franklin Pierce Bay in northern Umingmak Nuna (Ellesmere Island). After over 3,000 years in the eastern Arctic, the Tuniit represent the culmination of generations of environmental knowledge, innovation, and experience in a challenging landscape that requires intimate knowledge and planning for periods of resource scarcity. SiFi-4, a unique site consisting of a single Late Tuniit dwelling and associated midden, represents a departure from typical Tuniit sites surrounding Pikialasorsuaq (North Water polynya) and provides a rare opportunity to study the subsistence strategies of an isolated Tuniit household at a pivotal point in time. This research involves the zooarchaeological analysis of the SiFi-4 dwelling and midden, focusing on the midden faunal remains to analyze how hunting, resource management, and environmental stewardship were practiced during this period of transformation. New radiocarbon dates suggest that SiFi-4 was occupied at the very end of the Paleo-Inuit period, contemporaneous with the arrival of Inuit ancestors in the Pikialasorsuaq area. The study offers insights into their final adaptations within their environment and reveals that, rather than passive victims of climate or social upheaval, the Tuniit made deliberate choices that reflect both a deep understanding of their environment and a proactive approach to managing resources in a changing world affected by the Medieval Warming Period, Little Ice Age, and the arrival of early Inuit and Norse in the area. The SiFi-4 site suggests a pattern of avoidance of these newcomers by this Late Tuniit family. By examining the environmental decisions made by this isolated household, this thesis sheds light on broader human-environment relationships and provides lessons on resilience and ecological creativity in the face of radical environmental and cultural change—topics highly relevant in today’s context of climate challenges.