What could an archeologist infer from the fact that fish bones have been found at mountain sites of the Inca Empire, while potatoes, a mountain crop, have been found at coastal Inca sites? The different environmental sections of the Inca Empire traded with each other. The distance from the coast to the mountains was less than the length of the coast. The Inca diet was essentially the same no matter what region people were in. The coastal Inca and the mountain Inca taught each other their food-providing skills.