Sue, the largest and most complete Tyrannosaurus rex skeleton found to date, is discovered by Sue Hendrickson in South Dakota.

Sue, officially designated FMNH PR 2081, is one of the largest, most extensive, and best preserved Tyrannosaurus rex fossils ever found, at over 90 percent recovered by bulk.

Tyrannosaurus is a genus of large theropod dinosaur. The type species Tyrannosaurus rex, often shortened to T. rex or colloquially t-rex, is one of the best represented theropods. It lived throughout what is now western North America, on what was then an island continent known as Laramidia. Tyrannosaurus had a much wider range than other tyrannosaurids. Fossils are found in a variety of geological formations dating to the latest Campanian-Maastrichtian ages of the late Cretaceous period, 72.7 to 66 million years ago, with isolated specimens possibly indicating an earlier origin in the middle Campanian. It was the last known member of the tyrannosaurids and among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event.

Susan Hendrickson is an American explorer and fossil collector. Hendrickson is best known for her discovery of the remains of a Tyrannosaurus rex in South Dakota on August 12, 1990, in the Cheyenne River Reservation. Her discovery is the most complete skeleton of Tyrannosaurus known to science. This skeleton is now known as "Sue" in honor of her. It is on display at the Field Museum in Chicago, Illinois. She has also found other important fossils and artifacts around the world.

South Dakota is a double landlocked state in the North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Dakota Sioux tribe, which comprises a large portion of the population—with nine reservations in the state—and has historically dominated the territory. South Dakota is the 17th-largest by area, the fifth-least populous, and the fifth-least densely populated of the 50 United States. Pierre is the state capital, and Sioux Falls, with a population of about 213,900, is South Dakota's most populous city. The state is bisected by the Missouri River, dividing it into two geographically and socially distinct halves known as "East River" and "West River". South Dakota is bordered by North Dakota to the north, Minnesota to the east, Iowa to the southeast, Nebraska to the south, Wyoming to the west, and Montana to the northwest.