Waimea was the site of Camp Tarawa from 1943 to 1945. The camp was built by the 2nd Marine Division which had just fought the battle of Tarawa, hence the name of the camp. Those marines then trained there for their next campaigns before moving on in spring of 1944.
They were replaced by the 5th Marine Division, who used the area to train for the attack on Iwo Jima. After that campaign, those marines returned to the camp for further training, but the war ended before they were called into action again.
The camp was closed in November 1945 and returned to Parker Ranch, which had leased the land to the U.S. government for a nominal fee, with the proviso that it be returned to them in its original condition. This meant that few buildings from that time remain, but the land between Waimea and the South Kohala coast was littered with unexploded ordinance and shrapnel, some of which remains to this day.