When the relative pronoun is the object of a preposition, which is used instead of that, for example,  in which ,  for which ,  about which ,  through which , etc. (please see the third example below): Formal English: This is the man to whom I wanted to speak and whose name I had forgotten.he relative pronoun that can only be used in restrictive clauses. It can also be substituted for who (referring to persons) or which (referring to things) in informal English. Whereas that is often used while speaking, who and which are more common in formal written English.
For other uses, see Yellowstone (disambiguation). Yellowstone National Park is a national park located in the U.S. states of Wyoming, Montana and Idaho. It was established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872. Yellowstone was the first National Park in the U.S. and is also widely held to be the first national park in the world.
A+E Networks. President Grant signs the bill creating the nationâs first national park at Yellowstone. Native Americans had lived and hunted in the region that would become Yellowstone for hundreds of years before the first Anglo explorers arrived.heir images provided the first visual proof of Yellowstoneâs wonders and caught the attention of the U.S. Congress. Early in 1872, Congress moved to set aside 1,221,773 acres of public land straddling the future states of Wyoming, Montana, and Idaho as Americaâs first national park.