Earth oven baking pits are common occurrences within the Indigenous archaeological record of North America, yet archaeologists have paid minimal attention to evaluating how earth oven technology varies over the long term. The extensively sampled record of thermal features from Wyoming represents a unique opportunity to evaluate changes in earth oven technology through time and consider how earth ovens relate to other facets of Indigenous land use and subsistence strategies. This article is based on a sample of nearly 1,300 radiocarbon-dated features dating from 11,000 to 4000 cal BP. It evaluates diachronic shifts in feature morphology from the Early through Middle Holocene. Major changes in earth ovens include increasing size and the use of cook stone, first after 10,000 cal BP and then after 7500 cal BP. The observed variation indicates that Indigenous peoples adapted their cooking technology to address changes in types and quantities of resources processed, as well as changing requirements of the overall adaptive system. Recognizing how the diversity of thermal features and earth ovens change through time and across space allows researchers to ask more specific questions about Indigenous cooking technology, subsistence resources, and the role(s) these features played within broader lifeways.