Founded in 1974, the Black Hills Institute of Geological Research excavates and prepares fossils and makes museum quality replicas.

In 1992, BHI founded the Black Hills Museum of Natural History, a nonprofit paleontological museum in Hill City, S.D.

The privately owned institute is known for discovering well-known and largely intact Tyrannosaurus rex specimens including "Sue" and "Stan."

In addition to doing its ongoing field work, the institute operates an annual summer program that allows a limited number of volunteers to participate on a dig site called the Waugh Quarry, located in northwestern Wyoming near Hulett.

The site is part of the Morrison Formation of Late Jurassic sedimentary rock, where many of North America's dinosaur fossils have been harvested.

Sam Farrar, Waugh Quarry field manager, said the annual digs last anywhere from 10 days to five weeks, depending on the status of other projects. The program can accommodate as many as 35 volunteers at a time, many who stay for multiple days or weeks.

Although prospective volunteers must submit a biographical statement with their application, Farrar said they are chosen on a first-come, first-served basis.

For more information, go to http://www.bhigr.com/.