How Long Is the St. Croix River From Start to End?

Written by Katarina Betterton
Published: February 18, 2024
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In the central part of the United States, the Mississippi River runs deep through the country. To support such a massive river and life source, the Mississippi River needs hardy tributaries that feed it. Enter the St. Croix River: a long, winding body of water that stretches between two states and feeds the muddy Mississippi with clear, great water.

Learn more about the St. Croix River including how long it is, its ecology, what you can do for recreation on it, and how it compares to other tributaries of the Mississippi. 

How Long is the St. Croix River?

Riverboat on the St. Croix River in Minnesota

The St. Croix River flows between Wisconsin and Minnesota.


The St. Croix River is approximately 169 miles long. Starting in the Upper St. Croix Lake in Wisconsin, the vast majority of the St. Croix River’s length creates the border between Minnesota and Wisconsin — which is just over 160 miles long.

As for depth, the range of the river’s depth oscillates between 70 to 100 feet depending on location.

Ecology of the St. Croix River

St. Croix River during sunset with colorful sky at Interstate State Park in St. Croix Falls Wisconsin.

You can find great vistas of the St. Croix River during sunset at Interstate State Park in St. Croix Falls, Wisconsin.

©Aaron J Hill/

The St. Croix River remains an important part of the environment in Minnesota and Wisconsin. It’s named as a National Scenic Riverway and also under the protection of the National Park Service. The St. Croix also supplies power to the Minneapolis and St. Paul metropolitan by way of the Saint Croix Falls Dam.

The river remains protected by several different agencies and laws, including the National Wild and Scenic Rivers Act of 1968 and the Wild Rivers Conservancy. Its natural history spans back over one billion years ago — though some of the earliest signs of settlers have evidence of only 4,000 years of age. 

Dozens of different marine and semi-aquatic animals call the St. Croix home. Fish that anglers can often find include walleye, pike, muskellunge, smallmouth bass, catfish, and sturgeon. In the upper portion of the river, invasive zebra mussels converge. Several types of carp also exist. As both are invasive, the Minnesota Department of Natural Resources strongly encourages adventurers, anglers, and boaters to alert the agency of any encounters with the mussels or carp.

What To Do On the St. Croix River

Still water Lift Bridge, St. Croix River Bridge at Still water, Mn/DOT Bridge #4654, and Wis/DOT Bridge #M-61 is a crossing the St. Croix River between Still water, Minnesota, and Houlton, Wisconsin.

The St. Croix River was economically important several hundred years ago.

©Saibal Ghosh/

Between the sixteenth and nineteenth centuries, fur traders and lumberers used the St. Croix River to conduct much business. However, with the creation of the power dams, the river’s main use besides power is recreation.

Water-based recreation on St. Croix tends to draw the most tourists. Activities include:

  • Kayaking.
  • Fishing.
  • White-water rafting.
  • Paddle-boating.
  • Lazy river floating.
  • Swimming.
  • Canoeing.

However, the St. Croix riverbanks also have dozens of outcroppings and picturesque places to hike, picnic, and camp. State parks near the river offer programming for the whole family, the St. Croix Scenic Byway makes a wonderful weekend drive, and the overlooks offer stunning vistas for a relaxing afternoon, a photoshoot, or a place to meditate.

Where Is the St. Croix River Located on a Map?

wisconsin michigan on the map

St. Paul and Minneapolis get some power from the dams of the St. Croix.

©Alexander Lukatskiy/

When looking at a map of the United States, you’ll identify the St. Croix River between Wisconsin and Minnesota. Starting near Lake Superior, St. Croix begins to flow in the northwest corner of Wisconsin. It’s fed by the Namekagon, Snake, and Kettle rivers. 

After a few dozen miles, it creates half of the state border between Minnesota and Wisconsin, where it converges with the Mississippi. At the convergence, there’s a noticeable difference in water quality. The deep, clear navy blue waters of the St. Croix mix with the muddier brown waters of the Mississippi. 

Comparing the St. Croix River to Other Tributaries

St. Croix River in the fall season at Interstate State Park, Taylors Falls, Minnesota USA

Camping, hiking, boating, and fishing are just some of the popular activities on the St. Croix.

©Linda McKusick/

Compared to other tributaries of the Mississippi, the St. Croix isn’t the longest, deepest, or widest. The largest tributaries of the Mississippi River include:

  1. The Missouri River, at 2,522 miles in length.
  2. The Arkansas River, at 1,469 miles in length.
  3. The Red River of the South, at 1,290 miles in length.
  4. The Upper Mississippi River, at 1,250 miles in length.
  5. The Ohio River, at 981 miles in length.
  6. The Illinois River, at 273 miles in length.

Sailing the St. Croix

The St. Croix remains an integral part of life in both Minnesota and Wisconsin. Though cities and towns don’t rely on the river to live as they did thousands of years ago, it still creates power that brings light, electricity, and more to the nearby metropolitans. As a protected body of water, the St. Croix also encourages the flourishing of plant and animal life in the region.

The photo featured at the top of this post is © Matthew A Reddy/

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About the Author

Katarina is a writer at A-Z Animals where her primary focus is on dogs, travel, and unique aspects about towns, cities, and countries in the world. Katarina has been writing professionally for eight years. She secured two Bachelors degrees — in PR and Advertising — in 2017 from Rowan University and is currently working toward a Master's degree in creative writing. Katarina also volunteers for her local animal shelter and plans vacations across the globe for her friend group. A resident of Ohio, Katarina enjoys writing fiction novels, gardening, and working to train her three dogs to speak using "talk" buttons.

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