The closest mainland to Oahu is the island of Kauai, which is part of Hawaii. However, if you're referring to the nearest continental landmass, it would be the coast of California on the mainland United States, approximately 2,400 miles away. Oahu is part of the Hawaiian archipelago, situated in the central Pacific Ocean.
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The closest mainland airport is Ocean Ridge Airport (E55), in Gualala, California, but it is very small and privately owned, though open to the public. The closest publicly-owned mainland airport, which is significantly larger, is Little River Airport, in Little River, California. Depending on where in Hawaii you want to land, it is between 0.5 and 3 nautical miles further.
Alaska and Hawaii. If you go to the mainland, then California, Oregon, and Washington are the closest.
Casey which is 3400kmsaway
The closest distance from mainland to mainland is about 5,100 kilometers (from Boston, USA to Lisbon, Portugal).
The distance from Australia's island state of Tasmania to the closest point on the mainland is around 240 km.
The closest distance from mainland to mainland is about 5,100 kilometers (from Boston, USA to Lisbon, Portugal).
The closest distance is a mile and a quarter, to San Francisco.
The two Australian mainland capitals that are closest together are Melbourne and Canberra. They are approximately 465 kilometers (289 miles) apart. Canberra is located in the Australian Capital Territory, while Melbourne is the capital of the state of Victoria.
New Guinea is 150 km from mainland Australia. New Zealand is 1250 km from mainland Australia.
the closest mainland near Guam would be Thailand if that's what you mean