It would tie into the North American environments from the rest of the game too. Most of the following have plenty of small islands off their coasts or at the very least any fictional island would be as plausible as Los Cinco Muertes.
Tundra- Alaska, Hudson Bay area,
Taiga/Alpine- Washington, Oregon, British Columbia, Newfoundland
Temperate- New England, Chesapeak Bay area, L'Acadie
Desert/Arid- southern California, southern Texas, Mexico.
Semi-Tropical Marshlands- the Carolinas, Louisiana, Florida, eastern Texas
Tropical (Los Cinco Muertes)- Florida Keys, Hawaii, Puerto Rico, pretty much anything in the Caribbean or Pacific that any company with dino dna money could privately own.