Its physiography is greatly influenced by a geological structure of relatively undisturbed sedimentary strata. The island's form is a low-relief plateau, sloping to the south and west, with few parts higher than 330 m in elevation. Widespread surface exposure of the shale and siltstone formations supports abundant vegetation for this latitude and has given Bathurst Island a prolific wildlife population compared to other arctic islands.
Although discovered by Sir William Parry as early as 1819, and later explored by search parties seeking traces of Sir John Franklin, it was only after aerial reconnaissance by the Royal Canadian Air Force in 1947 that its final shape was revealed. The "peninsula" forming the western coast was discovered to be in reality a series of islands. Parry named the island for Henry Bathurst, 3rd earl of Bathurst, longtime British secretary of war and the colonies in the early 19th century.