The law to preserve and protect the Yellowstone environs was the first legislation to establish a national park. This area of some two million acres, about the size of Delaware and Rhode Island combined, stretched into what would become the states of Montana, Wyoming, and Idaho. In 1864 the federal government enacted the Yosemite Act to protect Yosemite Valley and its encircling peaks and the Mariposa Grove of Sierra redwoods; however, the state of California was given responsibility for the sites. When the U.S government passed a law in 1872 to protect Yellowstone on behalf of the entire country, it demonstrated the growing concern of many citizens that such a treasure be saved for future generations of Americans. As the world’s first national park, Yellowstone was unique to America. With its erupting geysers, hot springs, and forest of petrified wood, Yellowstone was spectacular and enormous.