The dishes cooked and eaten by Native Americans resulted from regional resources—available foods, fuels, and materials for cooking utensils. They consequently varied to some degree but shared basic forms and processes. The following discussion focuses on foodways at the point of contact and ensuing changes. Native American skills and their food-related artifacts began to change after European contact. Seventeenth-century stone knives, for example, were replaced with bartered iron knives, and clay pots were replaced with brass and copper kettles. Nineteenth-century cookstoves replaced hearth fires. Recipes evolved similarly. Indians in closest contact with newcomers changed faster. Those in remote and secluded areas or in large tribal communities maintained their early technologies longest. To keep old philosophies and foodways alive, some Native Americans, especially in the Southwest, continue to cook with fire in traditional pots. The dishes usually are prepared ritualistically on special occasions.