In 1876, a Chilean man by the surname of Campos and his wife Carmen Funes (known as "Pastoverde", translating into green grass) are said to be the ones who first settled into Plaza Huincul and welcomed travelers in case they needed a break; for example, the Pehuenches and Mapuches tribes.

The municipality gave its name to the Huincul Formation, a fossiliferous stratigraphic unit dating back to the Cenomanian stage of the Late Cretaceous.

Guillermo Heredia, the farmer who found the first specimen on his farm, mistook the uncovered fibula of the sauropod for a petrified tree trunk.

The next major Huincul Formation discovery came in 1993, when a local amateur fossil hunter by the name of Rubén Darío Carolini stumbled across a tibia from a large theropod whilst out in a dune buggy.

A team of specialists led by Rodolfo Coria were sent to excavate the fossil, and returned with an unusually complete skeleton (approximately 70%) including a partial skull.

They had found a huge new Carcharodontosaurid, its size likely equalling but potentially exceeding that of Tyrannosaurus Rex, and in 1994, the 12-13-metre carnivore was named Giganotosaurus by Coria.

Between 1997 and 2001, Coria and Canadian palaeontologist Phil Currie excavated what they thought to be a new specimen of Giganotosaurus in the Huincul Formation, but they noticed some abnormalities in the bone structure.