Where To Find Agates In North Dakota: 3 Options To Get You Started

For those willing to adventure out and collect interesting rocks, the world is your oyster.

One important factor every avid collector takes into consideration is location.

In this article, we’ll be discussing three locations where agates can be found within the state of North Dakota.

Where To Find Agates In North Dakota (A Visitor’s Guide)


The information provided in this article by YesDirt.com is for informational purposes and is subject to change. Laws are updated. Accessibility guidelines and restrictions change. Be sure to confirm the land status and collection rules before you travel to an unfamiliar location or collect any material.

Location #1: Cannonball River, Grant County

The first ideal location to try out stretches along the Cannonball River.

You’ll have to drive north of Selfridge along the ND-6 highway and stop just south of Breien, and before the junction of ND-6 and ND-24.

There are a few dirt roads you can access before this intersection.

However, the river will be within a fair walking distance, around 520 feet, if you decide to park near the ND-6 and ND-24 intersections.

While having easier river access, you might have to walk quite a bit just to get to the ideal spot, around 1 mile in total along the river bank.

However, if you were to stop your vehicle at another intersection about a mile south of the intersection mentioned above, you’ll only need to travel a total of 2505 feet, which includes getting to the river, and then walking along the bank.

Google maps show a farm or house within that area, so if you choose the shorter route, be sure to get that landowner’s permission before walking through private property to get to the river.

Once you’re on the river bank, however, North Dakota state law makes it clear that it’s public land, and you can continue your rock hunt.

The general area is quite flat with grasslands and bushes.

Once on the river bank, expect more sand and regolith characteristic of places near rivers.

You should see a row of trees across the river with a bit of farmland just beyond them.

The area you’re standing in should be the place listed to have agates.

Extracting them can be quite easy, especially after a good rain.

They will be present in washes and gravel beds along the Cannonball River.

If you’re lucky enough, you might be able to pick some up with your bare hands!

However, it’s recommended that you take along some tools with you just in case you need to dig, chisel, or carry food and water with you.

For example, you can benefit from a steel rock chisel that weighs around 22oz, a field shovel, some measuring tape, a standard steel chisel, and a sturdy backpack, if you’re willing to carry some extra weight.  

Most agates have irregular fractures and are about the size of golfballs.

They might be heavier than they appear.

You might also feel some waxiness upon touching them.

The quickest way to see if you have an agate or not is to split the rock apart with your rock chisel.

If you find different bands of color that run parallel to the sides of the cavity, you have an agate!

For the best display of your agate, take it to someone with a diamond saw.

That way you can have a picture-perfect agate to display in your collection at home.

Location #2: Dead Heart Slough, just outside Mandan, Morton County

This second location may be a bit trickier to get to, but it is fairly close to the city of Mandan.

If you travel westward (exiting the city) along I-94BL, cross the bridge going over the Heart River, go for 1 mile, turn left, and then make another left onto Sunny Road and keep driving until you reach 22 ½ avenue and turn left onto it.

You’ll come across a place known as Heart River Stables.

Be sure to ask the people there if it’s safe (or allowed) to travel along the Dead Heart Slough to the ideal agate location.

If possible, you’ll need to travel about 2000 feet in total to reach the spot that has known agate deposits.

Before getting there, you’ll need to travel away from the Dead Heart Slough, and should see a pathway that cuts across it.

Head south from that point.

The entire area should have a large cluster of trees and grass. Check the watery areas, specifically the gravel and sand, for your agate.

If conditions are too unsafe (or you don’t receive permission to tread private land), you can continue driving past River Heart Stables on 22 ½ avenue for about 1,530 feet.

From there, you can turn right (westward) onto a dirt road the rest of the way to the agate spot, measuring 1,374 feet towards a large cluster of trees.

Similar to the first location listed, be sure to equip the necessary rock-breaking and measuring tools for the job ahead.

When in doubt, crack the rock open to see if you have found what you’re looking for. 

Location #3: Heart River, South East of Dickinson, Stark County

The last location appears to be all on public land, or alongside the Heart River, so getting there shouldn’t need permission from a private land owner.

First, you’ll need to drive eastward on 36th Street SW, north of I-94. You’ll eventually arrive at an intersection of 36th and Lehigh Drive, which should appear as a dirt road.

Travel south on Lehigh Drive for about 1.3 miles until you begin approaching the Heart River.

Don’t cross over it or you’ll have gone too far.

After the 1.3 mile mark, you should see a flat worn-out area where you can park your vehicle.

Turn onto it and proceed to the sight on foot.

Depending on where you start, it should be about 500 feet to the point that has agate along the Heart River bank.

Your surroundings should look like a peninsula, with the river wrapping around a lightly forested area with an abandoned barn on it.

If you see all that from where you’re standing, you have arrived at your digging site.

As mentioned for the other places, it’s best to search for agates after rain, as the heavier agate should be exposed among the gravel you see around your feet.

There shouldn’t be too much digging required, but have a field shovel handy just in case.

If you find rocks that feel waxy to the touch, crack them open with your steel chisel to see if those distinct colorful bands are inside.

Wrap Up

So to re-cap, be sure to always ask permission before treading on private land, bring the necessary equipment to unearth the agates you seek, mind the weather when it counts, and keep digging until you find that special rock.

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where to find agates in north dakota