9 Things You May Not Know About the Soo Locks

There’s something for everyone in Sault Ste. Marie, from historic open houses, to spectacular vistas plus the opportunity to get a behind-the-scenes look at the great Soo Locks. Check out these nine interesting facts about the Soo Locks to inspire your visit from Sault Ste. Marie Convention and Visitor's Bureau.

A freighter passing through the Soo Locks
Soo Locks in Sault Ste. Marie | Photo Courtesy of Pure Michigan

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A man-made marvel and the busiest lock system in the world, by cargo tonnage, yes the Soo Locks! On average, between seven and ten thousand ships come through the locks during the shipping season each year.  Built in 1855, these locks connect Lake Superior to Lake Huron and beyond.  Some visitors come back every season, calling themselves Boat Nerds. They watch ships from all over the world use this free lock system.  Now here are some facts about the locking system and the St. Marys River.

1. 100% of iron ore passes through the locks annually

The value attributed to the iron ore shipped through the Soo Locks each year is $500.4 billion. An average of 80 million tons of cargo moves through them each year.

2. 7,000 passages are completed each year

Crews at the Soo Locks complete these lockages during the 42-week-long navigations season. They are open 24 hours a day. Can you take your personal boat through the locks? Yes, as long as you have a motor and permission from the lockmaster.

3. Visiting ships travel up to 2,342 miles

Ships from all over the world visit this port as the locks are a part of the Saint Lawrence Seaway, which connects Duluth, Minnesota to the Atlantic!

4. 22 million gallons of water are required to traverse a boat

The locks are powered by gravity itself!  Water moves in and out of the lock chambers by just opening and closing valves.

5. The largest boat that comes through is more than 1,000 feet long

There are 13-1,000 footers on the Great Lakes, and the largest boat that comes through the Soo Locks is the Paul R. Tregurtha, in at 1,013 feet 6 inches, which is larger than three football fields! The first vessels on the great lakes were 40-foot-long canoes.

6. It takes 9 hours to pass through

The time between Lake Superior and Lake Huron, it takes a freighter about 9 hours to pass through the St. Mary’s River system.

7. The locks allow boats to traverse a 21-foot drop 

A thick layer of bedrock holds back the waters of Lake Superior where it joins the St. Marys River. This drop prevented boats from passing through. This reddish sandstone lines most of Lake Superior southern shores and is about 1000 feet-thick. The Fairbanks Scale Company, which is still in business today, built the first permanent lock, State Lock.

8. The toll was once 3-4 cents per ton

From 1855 to 1881, this was the toll, but today it is free.

9. The propeller is from a former steamer

The propeller in Soo Locks Park is from a steamer named the Independence, which exploded just northwest of today’s locks. One crewman is said to have survived a trip down the rapids on a hay bale from the ship.

Now that you know more about the Soo Locks, come and visit the Soo Locks Park anytime from late March and Mid-January to see the freighters go through the locks and get up close and personal with this engineering marvel!