Which US state has the longest coastline?

Alaska's Coastline: The Numbers That Break Your Brain

When people think of long coastlines, places like Florida or California usually come to mind — sun-drenched beaches, tourist hotspots, iconic shorelines. But Alaska doesn't just beat those states. It obliterates them. Alaska's coastline stretches over 6,600 miles, which is more than the coastlines of every other US state combined.

Why So Much Coastline?

The secret is in Alaska's geography. The state is riddled with islands, inlets, bays, fjords, and peninsulas — all of which dramatically inflate the total length of its shoreline. The Alaska Peninsula alone juts hundreds of miles into the Pacific Ocean, and the Aleutian Island chain extends so far west that it actually crosses the 180th meridian, pushing into the Eastern Hemisphere.

Then there's the panhandle in southeastern Alaska, a narrow strip of land laced with thousands of islands and deep glacial fjords carved over millions of years by advancing and retreating ice sheets. Every twist and turn of that jagged edge adds miles to the total count.

How Is Coastline Actually Measured?

Coastline measurement is trickier than it sounds. Depending on the scale of the map you use, a coastline can appear longer or shorter — a quirk known as the coastline paradox. The more detailed your measurement, the longer the line gets, because you're tracing every tiny cove and rocky outcrop. The commonly cited 6,600-mile figure for Alaska uses a fairly general measurement. When measured in finer detail, estimates climb even higher — some sources put it closer to 33,000 miles when including tidal inlets and offshore islands.

For Context: The Runner-Up Isn't Close

Florida comes in second among US states with a general coastline of around 1,350 miles. California sits at roughly 840 miles. Alaska's 6,600 miles doesn't just edge out the competition — it laps it multiple times. You could drive from New York to Los Angeles more than twice and still not cover the total length of Alaska's coast.

What's Along That Coastline?

Alaska's coastline isn't lined with beach resorts and boardwalks. Much of it is remote wilderness, home to brown bears, sea otters, humpback whales, and tens of millions of migratory seabirds. Communities like Juneau, Sitka, Kodiak, and Ketchikan hug the coast, many of them only accessible by boat or plane. Commercial fishing — particularly for salmon, crab, and halibut — is one of the primary industries sustained by these waters.

The coastline also borders three separate bodies of water: the Arctic Ocean to the north, the Pacific Ocean to the south, and the Bering Sea to the west, giving Alaska a geographic diversity matched by no other state.

The Bottom Line

Alaska is already the largest US state by land area — about twice the size of Texas — so perhaps it shouldn't surprise anyone that its coastline follows suit. But the sheer scale of it still manages to stun. It's one of those facts that sounds like an exaggeration until you look at a map.