Some very well thought out responses here. I think we would all be naive to think that development will never happen on the Eastern Rim of Grand Canyon on Navajo lands. It is a Navajo Tribal Park already. In fact, it really probably should happen for the people who live nearby. The folks in the Bodaway-Gap Chapter and those who suffered through the Bennett Freeze deserve to have a way to make a good living, and they should cash in on the natural beauty of the area. While I am not a real big fan of what the Hualapai have done out west (read: sacred toilet seat and Quartermaster Air Assault Corridor), I do foresee some development at some point.
The thing about it is, the development needs to actually benefit the people. The Tramway project benefits the DEVELOPERS and the Navajo Nation President along with his buddies. This does not help the families who actually live in the area.
As it turns out, the GC Enlargement Act of 1975 empowers and frankly requires the Secretary of the Interior to work with the Navajo to develop areas for interpretation along the Eastern Rim (Marble Canyon area land controlled by the Navajo) to ensure the area is protected, while providing real opportunities to the Navajo people. Look for more on this to come in the very near future on the Rafting GC Yahoo/Facebook pages.