What was the 'progressive era conservation movement', and how did it take shape in the hetch-hetchy debate. be able to explain the hetch-hetchy debate, including important actors involved?

The Progressive Era Conservation Movement was a social movement taking place during the late 19th and 20th century that saw a resurgence in environmental conservation following the drastic exploitation of natural resources in the United States. Supporters of this movement included President Theodore Roosevelt who created state entities to preserve natural resources and lands. 

The Hetch-Hetchy debate discussed the incorporation of water resources into San Fransisco's city planning, specifically the damming of an important river in Yosemite in order to grow the new city or the conservation of wild lands. Congress debated the issue, pitting conservationists and preservationists against one another, eventually, conservationists were victorious seeing a dam built in the Hetch Hetchy Valley.