Thevenard Island is located approximately 22 kilometres (14 mi) off the coast of Onslow in the Pilbara region of Western Australia.

[6] The island can be reached by a ferry service operating from the mainland at Onslow, recreational boats, helicopter and light scenic plane.

[7] Thevenard Island is approximately 6 kilometres (4 mi) in length[4] and occupies a total area of 550 hectares (1,359 acres).

[9] Areas of deep sandy soil are found on the island supporting Acacia and Triodia shrubland and coastal heath scrub.

In addition, there are up to 31 species of migratory birds occurring in the Mackerel Islands area, including kestrels, quails, godwits, plovers, sandpipers and harriers.

[16] A total of nine reptile species have been recorded on the island including goannas, dragons, skinks, geckos and ta-ta lizards.

The company was granted a 25 hectares (62 acres) lease to build production facilities on Thevenard Island; the first oil was produced from the project in 1989.

[22] The Government of Western Australia's Department of Parks and Wildlife (now the Department of Biodiversity, Conservation and Attractions) conducted a pilot flatback turtle monitoring project on Thevenard Island in 2016, which continues annually, having identified Thevenard Island as an important turtle nesting site.

The pilot project was part of the North West Shelf Flatback Turtle Conservation Program's monitoring program, which was established to help understand the ecology and demography of the North West Shelf flatback stock, which includes populations found off the Pilbara and south-west Kimberley coasts.