The IEN also has an Environmental Code of Ethics which was written in Bear Butte, South Dakota in 1991. This code further helps to clarify their stance as an indigenous and environmental alliance. One of the key problems that IEN addresses in its Environmental Code of Ethics is that indigenous people culturally and Native Americans politically, are tied to their land. Native Americans in the United States and Canada are restricted to reservations if they want to maintain any kind of political nation idea. Similarly, indigenous people often have religious or ancestral ties to specific tracts of land. This unique relationship makes them less likely to leave, makes the land more valuable, and makes them even more staunchly opposed to polluting it in any way. Each year the conference is held in a different indigenous Nation.