Not only is Kodiak Island the largest island in Alaska, but it’s also the second-largest in the United States, following Hawaii’s Big Island. Kodiak Island covers 3,595 square miles, making it larger than Puerto Rico. The island is known for its brown bears called Kodiak bears, which are endemic to the island. The Kodiak National Wildlife Refuge, established by President Franklin Roosevelt, is home to some 3,000 of these bears.

Utah’s Great Salt Lake is home to 17 officially named islands. The largest is Antelope Island, which actually turns into a peninsula when lake levels are low. The island’s 40 freshwater springs provide ample water support to wildlife who can’t drink from the salty lake. Bison are the most populous group of animals on the island; the current herd consists of 550 to 700 creatures.

The Ten Thousand Islands archipelago is located in Collier County in southwestern Florida, near the city of Naples and just west of the Everglades. Despite the name, the chain is home to several hundred (not thousand) islands. At six miles long and four miles wide, Marco Island is the largest and most developed island in the archipelago.

Assateague Island is a 37-mile-long barrier island on the Atlantic Coast where over 300 wild horses roam freely. According to local legend, the horses arrived on the island after a 17th-century shipwreck, but there’s not much evidence to support that theory. Most of the island lies in Maryland, where these residents are called Assateague horses. The smaller portion of the island that is in Virginia is home to a second herd, called Chincoteague ponies.

The town and county of Nantucket consists of three islands, though Nantucket Island itself is the only island with public access. Tuckernuck is privately owned, while Muskeget is only inhabited by seals. These islands are located south of Cape Cod near Martha’s Vineyard. Nantucket was named after a Wampanoag Native American word meaning either “far-away land” or “sandy, sterile soil tempting no one.”

Captiva and Sanibel are barrier islands located along the coast of Fort Myers, Florida. These quintessential Gulf Coast towns boast everything from wildlife refuges to beachside resorts. The islands also have a rich history in the fishing industry and are home to over 50 species of fish and 250 types of seashells.

One of South Carolina’s most popular tourist areas, Hilton Head is a favorite among golfers, family vacationers, and nature lovers alike. The island’s Harbour Town Lighthouse sits on the southwest side of the island, but it isn’t a functioning lighthouse at all. It was built as a tourist attraction, which gave it the nickname “Fraser’s Folly” — after the architect who designed it in 1970.

A popular destination for LGBTQ+ travelers, the Fire Island National Seashore is a 26-mile protected area of beaches located off of Long Island in New York. The origin of the island’s name is up for debate: Some historians believe it was a misinterpretation of “five,” in recognition of the original five barrier islands, while others say the name could point to the island’s history of whaling, when whalers would boil down blubber on the beaches.

A popular summertime getaway, Mackinac Island is only accessible via ferry from either of Michigan’s peninsulas. The small island, with a circumference of only eight miles, is located in the Straits of Mackinac. Much of the forested island is a state park, and Mackinac is also known for its historic forts, yacht races, and the Victorian-style Grand Hotel, which lays claim to the world’s longest porch.

Covering 65 square miles, Acadia National Park takes up much of picturesque Mount Desert Island along the coast of Maine. Established in 1919, Acadia was the first national park east of the Mississippi River. Mount Desert Island is known for being Maine’s largest island and is also home to the charming port city of Bar Harbor.

Eighteen-square-mile Roanoke Island is located between the Outer Banks and mainland North Carolina. The English arrived here in 1584 and attempted to set up a colony, which was the birthplace of the first English child born in North America, Virginia Dare. However, the English soon faced supply shortages and attacks from Native Americans and later disappeared without a trace — only the letters “CRO” and “CROATOAN” were found carved on nearby trees. For this reason, Roanoke is sometimes referred to as the “Lost Colony.”

Tybee Island was once called “Savannah Beach” for its proximity to the city of Savannah, which is located only 18 miles away. The island — whose name comes from the Euchee Native American word for “salt” — is also Georgia’s easternmost point. It’s known for its wildlife and is a top nesting spot for endangered Loggerhead sea turtles.

Not only is the Big Island the largest of the Hawaiian islands, but it’s also the youngest — it was formed by volcanic activity over 600,000 years ago. In comparison, Hawaii's oldest island, Kauai, formed about 5 million years ago. The Big Island is also home to the largest active volcano in the world, Mauna Loa, and Kilauea, which has been erupting continuously since 1983.

Santa Catalina Island, commonly known as Catalina, is one of the Channel Islands, an eight-island archipelago along the coast of Southern California in Los Angeles County. The island was named in 1602 by Spanish explorer Sebastián Vizcaíno after St. Catherine (Catalina) of Alexandria, and today, it’s a popular tourist destination that is accessible via ferry from the mainland.

The San Juan Islands have no traffic lights, and many are accessible only by ferry during the summer. More than 170 islands make up this unspoiled archipelago, which is located in northwestern Washington near the Canadian border and popular for whale watchers. The largest islands of the 450-island archipelago are Orcas, San Juan, and Lopez.

Galveston is a major port city and tourist destination on the Gulf Coast of Texas. The city is located on Galveston Island, a barrier island that averages only two miles wide and boasts 32 miles of beaches. The island has a storied history with its involvement in the Mexican-American and Civil Wars, bringing in history buffs and beachgoers alike.

Key West is the westernmost island of the Florida Keys, and on its southern shore is a monument marking the southernmost point in the continental U.S. — just 90 miles north of Cuba. However, the marker is not technically at the southernmost point on the island — other areas on Key West, like the Key West National Wildlife Refuge, are actually a little farther south.

Martha's Vineyard is a historic New England island and popular tourist destination located off the coast of Massachusetts, south of Cape Cod on the Vineyard Sound. The Indigenous Wampanoag peoples called it "Noepe," meaning, “land amid the streams,” likely for its many inlets and ponds. The island is also home to the Flying Horses Carousel, the country’s oldest operating platform carousel, which opened in 1876.

The Outer Banks are a group of barrier islands that extend from Back Bay, Virginia, more than 175 miles south to Cape Lookout, North Carolina. The islands were the site of some of the earliest English colonies and are now a popular tourist destination. Hatteras Island is home to the Cape Hatteras National Seashore, where visitors can fish, windsurf, hike, and enjoy the region’s sandy unspoiled beaches.

Home to over 7 million people, Long Island covers 1,401 square miles in southeastern New York. The island’s western end includes the New York City borough of Brooklyn, which is separated from Manhattan by the East River. The island’s eastern Atlantic coast is known for beach towns like Montauk and the Hamptons, a popular summer retreat for city dwellers.