The Hawaiian Archipelago consists of eight large islands and 124 small islands, reefs, and shoals. It stretches for over 2,400 km from 19 degrees - 28 degrees N to 155 degrees -178 degrees E. It can be divided into two distinct regions: the Northwestern Hawaiian Islands (NWHI), primarily uninhabited atolls, islands, and banks accounting for the majority of U.S. reefs, and the Main Hawaiian Islands (MHI) largely made up of populated, high, volcanic islands with non-structural reef communities, fringing reefs, and two barrier reefs.