Hydropower is one of the cheapest and cleanest ways to generate electricity, but it does have a significant impact. In the Canadian province of Manitoba, dams built over the last three decades have damaged the land and destroyed the traditional lifestyle of Cree Indians there. Manitoba Hydro provides hydroelectric power for three provinces in Canada and parts of the United States. Now, with the demand for electricity increasing, the utility’s biggest U.S. customer, Excel Energy, wants to buy additional power from the company. Some of the Cree people are against this and have enlisted activists from the U.S.