Alaska's Coastline Is Longer Than All 49 Other States Combined — US Coastlines Ranked

The map — US ocean coastline by state

Each US state is coloured by its NOAA general coastline length and labeled with its exact mileage. Coastal states are outlined in ocean-blue to distinguish them from the landlocked states.

The colour scale uses a square-root transformation so mid-tier coastal states — Maine (228 mi), Massachusetts (192 mi), the Carolinas — remain visually distinct rather than being crushed to near-black against Alaska's 6,640-mile outlier.

Alaska's label dominates the upper-left inset because no other state is within an order of magnitude. Its coastline alone exceeds the combined Atlantic shore from Maine to Florida plus the Pacific shore from Washington to California.

On the Gulf, Florida and Louisiana register the darkest fills outside Alaska. Florida because two oceans border it (Atlantic east, Gulf west); Louisiana because of its fractal Mississippi delta.

The Carolinas, despite ranking 7th and 11th by general coastline, are quietly the longest stretch of single-state Atlantic shore between New England and Florida.

NOAA general coastline figures in statute miles. Coastal-state outlines emphasised in ocean-blue. Mileage labels render at each state's population-weighted centroid.

Top 10 states by ocean coastline

The bar chart ranks the ten states with the longest open-ocean shore. Alaska's bar (in ocean-blue rather than forest green) calls attention to the scale break.

At 6,640miles, Alaska is roughly five times longer than Florida (rank 2) and almost eight times longer than California (rank 3). Every bar after Alaska looks truncated — that's the actual data, not a chart artifact.

Three structural clusters emerge in the top 10.

Pacific states — Alaska, California, Hawaii, Oregon, Washington — all rank in the top 12. They share a continental shelf with few interrupting bays, which keeps their tidal/general ratio low compared with Atlantic states.

Gulf states— Florida, Louisiana, Texas — benefit from the Gulf of Mexico's shallow, fractal shoreline. Louisiana's tidal shore (7,721 mi) is the third-longest in the US despite its general coastline only ranking 5th.

Atlantic states — North Carolina, Maine, Massachusetts, South Carolina — anchor the mid-rank with classic barrier-island and bay-and-headland geometry.

The table below shows the same top-10 ranking with general and tidal shoreline side-by-side.

Watch the tidal/general ratio: Maine's is 15×, Virginia's is 30×, Maryland's (further down the list) is over 100×. Higher ratios mean more intricate coastline geometry — and almost always more biologically productive estuaries.

Shortest 5 ocean coastlines

The bottom of the ocean-coastline ranking is mostly geography trivia.

New Hampshire's 13 milesis the shortest of any state with ocean access — a thin sliver between Massachusetts and Maine running through Hampton, Seabrook, and Rye. It's the perennial pub-quiz answer for "smallest US coastline" and explains why Portsmouth is the only deepwater port in the entire state.

Delaware's 28 miles are essentially the mouth of the Delaware Bay, between Cape Henlopen and the Maryland line.

Maryland's 31 miles all sit on Assateague Island and a small DelMarVa peninsula sliver — yet Maryland has 3,190 miles of tidal shoreline thanks to Chesapeake Bay (the highest tidal-to-general ratio of any US state, over 100×).

Rhode Island's 40 miles all sit on the southern shore facing Block Island Sound.

Mississippi's 44 miles sit between Louisiana and Alabama on a fragmented Gulf coast.

Top 10 states by tidal shoreline

Tidal shoreline is the more inclusive measurement: it counts every bay, estuary, sound, tidal river, and inlet that the ocean reaches into.

For most states the tidal figure is several times larger than the general figure — sometimes dramatically so. The ranking changes order significantly under this metric.

Maryland is the most dramatic mismatch.

Its general coastline is just 31 miles — barely visible on a national-scale map. But its tidal shoreline is 3,190 miles, more than 100× larger.

The Chesapeake Bay's western shore alone (Annapolis to Smith Point, Virginia) has more tidal shoreline than the entire Pacific shore of Washington state. Over 150 named tributaries reach into Maryland; the Bay's finger-and-river geometry is structurally similar to a fractal, which is why the resolution-dependent measurement explodes.

Louisiana climbs from 5th to 3rd when ranked by tidal shoreline rather than general coastline.

Its 7,721 miles of tidal shore reflect the Mississippi Delta's fragmented marshland — a constantly-changing maze of distributary channels, oxbows, and bayous that adds and loses shoreline yearly.

Florida, Alaska, and Maine all climb significantly for the same reason: complex bay-and-island geometry that the general-coastline metric flattens but tidal shoreline captures.

The choropleth below shades each state by tidal shoreline on the same square-root scale. The pattern is visibly different from the general-coastline map: Northeast, Mid-Atlantic, and Gulf states all darken noticeably.

This is the map a fisherman, a tidal-power engineer, or an estuarine biologist actually cares about.

Great Lakes states (separate category)

The Great Lakes are freshwater, so they don't count toward NOAA's ocean coastline numbers.

But they hold roughly 21% of the world's surface freshwater and create a shoreline regime that operates by similar rules. Eight US states front one or more Great Lakes.

Three of those (Michigan, Minnesota, Wisconsin) have only Great Lakes shore as their water frontage. Another five (Illinois, Indiana, Ohio, Pennsylvania, New York) have it alongside other water boundaries.

Michigan dominates the ranking at 3,288 miles — more than the next three states combined.

Michigan fronts four of the five Great Lakes (Superior, Michigan, Huron, Erie); the only Lake it doesn't touch is Ontario. Both peninsulas (Upper and Lower) have substantial coast on multiple lakes, which is geographically unusual.

Wisconsin's 820 miles (Superior + Michigan) is a distant second.

New York and Pennsylvania appear in both rankings.

New York's 577 miles of Great Lakes shore (along Erie and Ontario, including the spectacular Thousand Islands stretch) sits alongside its 127 miles of Atlantic coast on Long Island.

Pennsylvania is the only state with shoreline of three kinds: 51 miles of Lake Erie shore, 89 miles of tidal shoreline (on the tidal Delaware River up to Trenton), and zero general ocean coastline.

Total US Great Lakes shore: 5,345 miles — roughly the driving distance from Seattle to Boston.

Complete ranking — all 50 states

Every US state, sorted first by general (ocean) coastline length and falling back to Great Lakes shoreline for states without ocean access.

Twenty-three states have measurable ocean coastline. An additional eight front a Great Lake. The remaining nineteen are entirely landlocked.

Tap any state name to download the corresponding blank printable map.

Patterns to look for as you scan the table:

The 100–300 mi cluster(Virginia, Massachusetts, South Carolina, Oregon, Maine, North Carolina) is the "classic" American coastline — bay-and-headland geometry on the Atlantic and Pacific.

The sub-100 mi states (Mississippi, New Hampshire, Delaware, Maryland, Connecticut, Rhode Island) each have only one narrow window to the sea.

The 1,000+ mi states are the two-ocean and Aleutian outliers — Alaska, Florida, California, Hawaii.

Methodology

All figures are NOAA published measurements from the Office for Coastal Management. NOAA reports two coastline metrics:

• General coastline — the open-ocean-facing shoreline, measured at the smallest tidal embayment that would close it off. Excludes inland bays, sounds, estuaries, and tidal rivers. This is the headline number used in most rankings.
• Tidal shoreline — includes all of the above plus every bay, sound, estuary, and tidal river. For most states this number is 3-100× larger than the general coastline.
• Great Lakes shoreline — separately maintained by NOAA Coastal Management Program. Eight US states front one or more Great Lakes.

NOAA's coastline measurements use a standardised methodology developed in 1939 by the Coast and Geodetic Survey, updated as shoreline mapping has improved. The figures are directly comparable between US states but should not be compared to other countries' coastline figures because measurement resolution differs internationally (the "coastline paradox": coastline length depends on the resolution of the measurement).

Source: NOAA Office for Coastal Management. The Congressional Research Service report RL34547 is the most widely cited published compilation. Great Lakes figures: NOAA Coastal Management Program. All figures in US statute miles (1 mi = 1.609 km).

Download the dataset

The full 50-state dataset is available under Creative Commons BY 4.0. Use it for journalism, research, school projects, or your own analysis. Attribution required: "SimpleMapLab (2026). US State Coastlines Dataset. https://www.simplemaplab.com/studies/state-coastlines".

Related on SimpleMapLab

• The Loneliest Towns in America — companion study, remoteness ranking
• The 100-Mile Radius Around Every US State Capital — another 50-state ranking
• Elevation Finder — check any coastal point's elevation
• Distance Between Two Places — measure your own coast-to-coast distances
• Blank Map of the United States — printable national map
• The Largest US Counties by Area — many of which are coastal