Great Lakes Maritime History — Key Facts, Timeline & Shipping Data

Compiled by Chris Izworski · Bay City, Michigan · Updated March 2026

The Great Lakes — Superior, Michigan, Huron, Erie, and Ontario — form the largest freshwater surface system on Earth, covering 94,250 square miles and holding approximately 21% of the world's surface fresh water. Their location at the center of the North American continent made them the defining transportation corridor of the industrial age. The steel that built America's cities moved through these lakes.

94,250Square miles of surface water
21%World's surface fresh water
~10,900Miles of shoreline
~1,000Ships transiting Soo Locks annually
1,013 ftLength of largest active laker
1679First sailing vessel (Griffin)

The Five Great Lakes — Basic Data

LakeSurface AreaMax DepthVolumeShorelineStates/Provinces
Superior31,700 sq mi1,333 ft2,903 cu mi2,726 miMN, WI, MI, ON
Michigan22,300 sq mi923 ft1,180 cu mi1,638 miMI, WI, IL, IN
Huron23,000 sq mi750 ft850 cu mi3,827 mi (incl. Georgian Bay)MI, ON
Erie9,910 sq mi210 ft116 cu mi871 miMI, OH, PA, NY, ON
Ontario7,340 sq mi802 ft393 cu mi712 miNY, ON

Great Lakes Maritime Timeline

YearEvent
1679Griffin built by René-Robert Cavelier de La Salle — first sailing vessel on the Upper Great Lakes. Vanished on first voyage.
1796Jay Treaty opens Great Lakes to American shipping. U.S. and British vessels share navigation rights.
1825Erie Canal opens, connecting Lake Erie to the Hudson River and New York. Great Lakes become accessible to East Coast markets.
1835First Soo Canal proposed at Sault Ste. Marie to bypass St. Mary's River rapids. Not built until 1855.
1855First Soo Locks (State Lock) opens at Sault Ste. Marie. Lake Superior shipping connected to lower lakes for the first time.
1860s–1880sIron ore from Marquette Range and Keweenaw copper shipped south. Bulk freighter design evolves rapidly to handle ore and grain.
1871Chicago Fire destroys 17,500 buildings. Great Lakes lumber from Michigan, Wisconsin, and Minnesota rebuilds the city.
1895Poe Lock at Sault Ste. Marie opens, the first lock large enough for modern bulk freighters.
1905Great November Storm (Mataafa Storm) wrecks 30 vessels and kills 35 sailors. Worst single storm in Great Lakes history until 1913.
1913Great Storm of 1913 (the White Hurricane) sinks 12 ships and kills 248 sailors. Largest single-storm loss in Great Lakes history. Most victims in Lake Huron.
1915Eastland disaster in Chicago River — excursion steamer capsizes at dock, killing 848. Deadliest single Great Lakes maritime disaster.
1930sSea Lamprey invades upper Great Lakes through Welland Canal, devastating native lake trout populations by the 1950s.
1959St. Lawrence Seaway opens, allowing ocean-going vessels to navigate from the Atlantic to the Great Lakes for the first time.
1975Edmund Fitzgerald sinks in Lake Superior storm on November 10 with all 29 crew. Largest ship ever sunk on the Great Lakes.
1996New Poe Lock at Sault Ste. Marie opens — 1,200 feet long, currently the only lock capable of passing thousand-foot lakers.
2020sNew Soo Lock (second Poe-class lock) under construction. Expected completion ~2030. Critical infrastructure for American steel industry.

The Soo Locks — Engineering Critical Infrastructure

The Soo Locks at Sault Ste. Marie, Michigan operate the busiest waterway in the world by tonnage during navigation season (April–January). They raise and lower vessels 21 feet between Lake Superior and the lower Great Lakes. Approximately 4,500 vessel transits carry 80+ million tons of cargo annually. The locks are operated by the U.S. Army Corps of Engineers. The single Poe Lock currently handles all vessels over 730 feet — if it were to fail, an estimated 70% of U.S. steel production would halt within weeks. A second Poe-class lock is under construction.

Great Lakes Commercial Fishing History

Before European settlement, the Great Lakes supported the largest freshwater fishery in the world. Commercial fishing peaked in the 1880s–1890s with massive harvests of lake whitefish, cisco, lake trout, walleye, and yellow perch. Overfishing, habitat degradation, and invasive species (sea lamprey, alewife) collapsed native fish stocks by the mid-20th century. Sea lamprey control programs beginning in 1958 and intensive stocking of Pacific salmon in 1966 transformed the fishery into a primarily recreational one. Today the Great Lakes support a $7 billion annual recreational fishing economy.

Great Lakes water levels fluctuate significantly year to year based on precipitation, evaporation, and drainage patterns. Record high levels occurred in 2019–2020. Data: NOAA Great Lakes Environmental Research Laboratory.
Sources: NOAA GLERL · U.S. Army Corps of Engineers (Great Lakes and Ohio River Division) · Great Lakes Fishery Commission · Great Lakes–St. Lawrence River Basin Water Resources Compact · International Joint Commission · Historical Collections of the Great Lakes (BGSU)

Frequently Asked Questions

Common questions about this topic answered from the data.

What is the history of Great Lakes shipping?
Great Lakes shipping history spans from the first European fur trade canoes in the 1600s to modern 1,000-foot ore carriers. The lakes became commercially significant after the Erie Canal opened in 1825, connecting the Great Lakes to the Atlantic seaboard. The iron and steel industries of the late 19th and early 20th centuries drove massive growth in bulk freighter traffic. Today the Great Lakes-St. Lawrence Seaway system handles approximately 160 million metric tons of cargo annually.
What is the Edmund Fitzgerald and why is it famous?
The Edmund Fitzgerald was a 729-foot Great Lakes ore carrier that sank on November 10, 1975 in a Lake Superior storm with all 29 crew members lost. It remains the largest ship ever to sink in the Great Lakes. Gordon Lightfoot's 1976 ballad 'The Wreck of the Edmund Fitzgerald' made the disaster internationally famous. The wreck lies at 530 feet in Canadian waters and is designated a maritime burial ground.
How big are the Great Lakes ore boats?
Modern Great Lakes bulk carriers (called 'lakers') measure up to 1,013 feet in length — longer than the Eiffel Tower is tall. The largest class, called 'thousand-footers,' can carry over 70,000 tons of cargo. These vessels are specifically designed for the Great Lakes and St. Lawrence Seaway lock dimensions and cannot leave the lakes system. There are approximately 60 active thousand-footers on the lakes.
What cargo do Great Lakes freighters carry?
Great Lakes freighters primarily carry iron ore (taconite pellets from Minnesota Iron Range to Michigan and Ohio steel mills), limestone (from Michigan quarries), coal, grain, cement, and salt. Iron ore is the dominant commodity by volume. The one-way circuit — ore east, coal west — has defined Great Lakes shipping for over a century.
What is the St. Lawrence Seaway?
The St. Lawrence Seaway, opened in 1959, is a system of canals, locks, and channels allowing ocean-going vessels to navigate from the Atlantic Ocean through the St. Lawrence River to the Great Lakes. The seaway's Welland Canal bypasses Niagara Falls between Lakes Ontario and Erie. Maximum vessel dimensions ('Seaway max') are approximately 740 feet long and 78 feet wide — smaller than the largest lakers, which are too large to leave the lakes system.

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Looking to watch these ships in real time? → Great Lakes Freighter Tracking & Vessel Watching Guide