It was established by joining the former Gurig National Park and the Cobourg Marine Park. Its name derives from the local Garig language, and the words gunak 'land' and barlu 'deep water'.[3]
The national park consists of all land of the Cobourg Peninsula, of Burford Island, the Sir George Hope Islands (from west to east Greenhill, Wangoindjung, Warldagawaji, Morse, Wunmiyi), Mogogout Island and Endyalgout Island (117.4 km2) to the south of the peninsula, and of adjacent waters. Croker Island, although close east of the peninsula, is not part of the park.