Your next river trip can skip crowds and be accomplished at the drop of a hat.

Annie and I often canoe the Le Sueur River near Mankato. It’s a go-to when we want an easy, off the path adventure. Similar to the nearby (and more popular) Blue Earth River, the Le Sueur offers interesting rock formations, a faster drive between access points, and more opportunities to get out of the boat to wade or swim. Go in June or early July for high water.

By the time the Le Sueur River passes under the Highway 16 bridge, it has meandered through hardwood forests and open fields all the way from Hope, MN.  Near the divide, a difference of a few feet could send a drop of water into the Le Sueur and travel west, or north in the Straight River. But I digress…

To start the trip, drop the boat at the Highway 16 access. At this time, lock the boat up to the sign, leave someone to watch it, or just be trusting. But don’t stress too much, the trip back is under 15 minutes.

Getting there: Take Stoltzman Road south out of Mankato where it becomes Highway 16, cross Highway 90, go down a big hill, cross the river, then take an immediate right (west) into the gravel access parking lot. (Google Maps: 18500 568th Avenue, Mankato, MN).

After dropping the boat, we take the broke-in car to the Highway 90 take-out so it’s ready for a wet dog. The Highway 90 take-out technically services two rivers and is located on the Blue Earth (downstream from where the Le Sueur dumps in).

If you aren’t in a rush, take a moment to stop at the Fort Lehillier Historical Marker located at the beginning of the access road from Highway 1. Legend has it that in 1700 A.D. Pierre-Charles Le Sueur (trader and explorer that came to mine the “blue earth”) left a cache of supplies somewhere along the river. Later, this fort was abandoned and the cache remains to be found…

Getting there: Head north on Highway 16 from the put-in. Take a left (west) on highway 90. As you descend into the valley, you’ll see the ski-hill on your right. At this point, take a left on Highway 1. Then, a quick right onto the access road to the parking lot. Park your car next to the boulders. The river is a little further down the gravel road to the bridge. (Google Maps: Fort Le Hillier Landing River Access).

Once you’re back to Highway 16, it’s time to finagle the boat down the steps and push off into the calm current of the Le Sueur River.

Check out the South Route Trail for a way to bike between access points.

This first stretch of the Le Sueur River is reminiscent of the its prior journey to this point.

Immediately on the left, an old bridge pier can be seen stubbornly commanding this forlorn bank of the river. It’s fun to imagine how the Le Sueur River’s path has changed since that feat of engineering was in service.

After finishing the first mile, there are two significant bends that have eroded clay banks. Prairie rivers tend to erode sideways, creating sweeping meanders (curves) into the surrounding landscape. On the other hand, mountain rivers have energy from elevation changes and erode down into the ground.

Eventually, the Maple River joins the Le Sueur River from the south. It dumps a significant amount of sand to form a nice beach to stop at for your first break in the action.

Standing at the Maple River confluence, we look ahead to the mother of all clay banks rising from the water. As far as I know, this cut is unprecedented in the area. Just before this clay bank is a large, long sandbar jutting out from the right bank of the river.

After the short rapids and in the shadow of the clay bank, pull off to walk towards a spring bubbling just below the high water mark of the river bank.

If you visit the spring, note the iron rusting out of the groundwater as it becomes exposed to the air. Iron can only be dissolved in water when there is no oxygen, when it reaches the surface the iron meets with oxygen and turns to rust.

Dolomite Limestone Outcrops

Turning past the clay bank, the Le Sueur River straightens for a stretch and as we near the next curve I point out the dolomite (limestone) outcrops tucked into the trees on the left hand side.

This marks a special point in the river’s journey. Up and until now, the river has been grinding its path through clay, sand, and rocks left behind by the glaciers that once covered Minnesota.

This dolomite is the first rock formation found under all the glacial sediments in the area. It’s a remnant of a long forgotten coral reef that was swimming with life under an ancient sea. It’s similar to the Kasota Stone mined near Mankato and found on buildings around our country (including the St. Paul Capitol building).

Looking closely at this location, the upper tip of Jordan Sandstone can be seen poking out from underneath the dolomite. Although, this can only be seen during low water levels. If you don’t find the sandstone, don’t despair, there are big cliffs of it further on.

Kaolinite Clay Outcrop

Leaving the dolomite behind, the river takes us on a stretch of calm water. After a cliff colonized by swallows lies one of the most beautiful stretches of the Le Sueur River. With choppy rapids and tall cottonwoods sporting a large eagle’s nest.

At the end is a sweeping bend that turns almost 180 degrees, here you can see a Kaolinite clay outcropping. Compared to the underground sequence of rocks, this clay is older and lies beneath the area’s limestone.

The next spot to point out is a larger stretch of rapids with several large boulders. It’s best to tackle these head on, but leave room to maneuver and steer past the big rocks.

Looking ahead to the left, a small outcrop of Jordan Sandstone presents itself, a precursor to the larger cliffs to come. Passing this small outcropping there’s a large power transmission line crossing the Le Sueur River. Use this to get your bearings if they have been lost, ignored, or forgotten.

Next, the Le Sueur River switches it’s cut bank. A bluff appears on the left with tall hardwood forests rising from the water. A shallow stretch gives way more rapids and a larger sandstone cliff beyond. Recent floods have scoured these cliff sides, leaving fresh rock exposed.

Wherever this rock appears, it is sometimes possible to see groundwater discharging near the base. This water will be clear, cold, and often leave behind iron deposits as it joins rivers. We stop here for a lunch on the sand bar.

Passing the Kern Bridge

Leaving these cliffs behind, notice the rip-rap on the right. This marks the site of the former Kern Bridge with a now abandoned concrete stream gauging station beyond. Two more bends in the Le Sueur River bring us to the largest outcrop of Jordan Sandstone on the trip.

Further on is the Red Jacket Train Trestle. This marks the stretch of river I called my backyard as a kid.

Having ground it’s way through limestone, clay, and sandstone, the Le Sueur River reaches it’s next rocky adversary: the St. Lawrence Formation. After the trestle, this reddish-orange sandstone shows itself. Take a moment to appreciate the age of this sandstone. It has been in place since the Cambrian period, almost 500 million years ago.

Leaving the mud behind, we float to the end of the Le Sueur River as it joins the Blue Earth River. Being the longer and bigger stream, the Blue Earth claims naming rights of the waterway for only three more miles before meeting the Minnesota River. After passing the Blue Earth confluence, keep your eye on the bridge ahead and exit to the right. Here, we bring our car down from the parking lot and load up to go.

Hopefully you’ve enjoyed the Le Sueur River as much as I do, the geologic history and personal memories bring me back year after year to enjoy.

If you rather go hiking instead of canoeing, check out our post on Waterfowl Production Areas.

Nearby Public Land You Can Explore Tomorrow

TLDR

Drop the boat at the Highway 16 Access

Take the car with the roof racks to the Highway 90 Access

Drive back and start the trip from Highway 16

Make sure to appreciate the Rock Outcrops along the way

Cook a meal, swim, or lighten a cooler on a sandbar

Take-out at Highway 90

Drive back via Highway 90 to get your car at the put-in

This post was written by Nick Schmitz, June 2020.