Mili and Nadrikdrik are paired atolls at the south-eastern perimeter of the Marshall Islands, which may rank amongst the richest and healthiest reef systems in the world. The atolls are home to spectacular and distinctive biota including striking majestic gorgonian sea fans, large patches of soft corals, large populations of sharks, and whales and dolphins. The marine environment of the atoll is high in rare and threatened species. The terrestrial and littoral aspects of the atoll contain a range of habitat types and communities including mangroves, fresh surface water (rare on low-lying atolls) and significant bird rookeries.
Mili Atoll is inhabited and is in use by the community as a food source, however, the area proposed is uninhabited. The proposed Mili Atoll Nature Conservation Area is listed as one of the key biodiversity areas in the Conservation International Polynesia-Micronesia Hotspot.