The Hawaiian Islands are at the end of a chain of volcanoes that began forming over 70 million years ago!
The youngest and largest of the Hawaiian Islands is the Big Island of Hawaii, and as lava continues to flow, the island is still forming to this day! There are about 143 Hawaiian Islands in the chain that is approximately 1500 miles long. Many of these islands have not yet reached sea level.
Here are the approximate ages of the youngest and largest Hawaiian Islands.
Big Island of Hawaii – Less than 700,000 years old (and still growing!)
Maui – 0.8 – 1.3 million years old
Kaho'olawe – 1.03 million years old
Molokai – 1.3 – 1.8 million years old
Lana'i – 1.3 million years old
O'ahu – 2.2 – 3.4 million years old
Kaua'i – 4 million years old