[1] The island group was given its English name in 1770 by James Cook because they reminded him of the way sugar was stored in heaps in Europe.

In 2013 New Plymouth District Council unanimously agreed to gift the protected area back to the government for treaty settlement negotiations with Taranaki and Te Āti Awa iwi.

The earth works to reclaim land for the New Plymouth Power Station[9] reduced the island's size and permanently connected it to the mainland.

With caves, rockpools and surrounding beaches it was mostly destroyed from excavations for the cooling water inlet and land reclamation for the power station.

[13] Mataora, Motu-o-Tamatea, Moturoa Island, and Mikotahi were hunting, fishing and gathering grounds and places of refuge for local inhabitants and the Taranaki and Te Āti Awa for hundreds of years.

Concern over oil exploration led to strengthening of the protection, through the enacting of the 1991 Sugar Loaf Islands Marine Park Act.

The Sugar Loaf Islands, along with onshore pinnacles such as Paritutu (153 m (502 ft)), represent the oldest volcanic activity on the Taranaki peninsula.

Dating between 1.7[20] and 1.74[21] million years of age, the islands are believed to be the remains of a ring fracture or feeders to eroded volcanic vents,[20] and are composed of a porphyritic hornblende andesite.