[8] As of 2020, it has an area of 39,159 square kilometres (15,119 sq mi).

Its name is derived from the mountain range which was named in June 1989 as the Costello Range after John Costello, a pastoralist who established the Lake Nash Station in 1890 after moving his cattle from the Valley of the Springs Station which was located on the course of the Limmen Bight River.

[1] Costello includes the following places listed on the Northern Territory Heritage Register – the Eldo Rocket Shelters Annitowa and the Eldo Rocket Shelters Argadargada.

[11][12] The 2016 Australian census which was conducted in August 2016 reports that Costello had a population of 12 people.

[2] Costello is located within the federal division of Lingiari, the territory electoral division of Barkly and the local government area of the Barkly Region.