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TerraClear “rocks” Idaho Farm Bureau convention

By Paige Nelson

For Idaho Farm Bureau Federation

FORT HALL – Idaho farmers are proud of the rich, volcanic soil in which they grow their crops.

But that fantastic soil originated from the erosion of rocks and, unfortunately for many farmers, those ancestral rocks are still nestled in, snug as can be, in many Idaho fields.

Trevor Thompson, president of TerraClear Inc., says that’s where his new rock-picking machine steps in. Because TerraClear is based out of Grangeville, Idaho, and Bellevue, Wash., basically all of the research and development done on the rock picker was performed in our neck of the woods.

“We know it works in Idaho,” says Thompson.

Picking rocks in 2022

The picker, which was showcased during Idaho Farm Bureau Federation’s annual convention in December, is designed with a mechanical arm fitted with rotating tracks that act as teeth. Behind the arm is a slotted bucket with tines 3 inches apart. This allows the bucket to hold the rocks, letting the dirt fall through. The arm is operated with a joystick and moves left and right to distribute the rocks in the bucket efficiently.

Ultimately, explains Thompson, if you can get the bucket in the right spot, you just push a single button and the whole picking motion — tracks running and the arm going down at the rock — happens all on its own.

The rotating tracks then work to spit the rock into the bucket.

That’s just the mechanical side of TerraClear. Using artificial intelligence and drone footage, the company also provides field mapping of rocks, up to 500 acres per day.

The AI looks at all the rocks in the field and creates the most efficient path for the operator to follow as they head out to work.

The AI even identifies the size of each rock in the field.

“We map fields so farmers know exactly where the rocks are, classified by size,” Thompson says. “We designed a precision rock picker that hyper-efficiently removes the rocks. It allows farmers to travel directly to their problematic rocks and quickly remove them without disrupting the soil.”

A better way

TerraClear claims it all began with the “classic founder story.” The idea started where many good ideas start, in a field.

The founder was picking rocks by hand and had the same thought as anyone who has ever picked rocks: “There’s got to be a better way to do this!”

He took his problem to Seattle where he had a network of professionals, from mechanical engineers to AI gurus and robotics specialists, help find the answer. According to Thompson, the solution was two-fold:

• First, identify where all the rocks are. There’s a huge efficiency problem in doing that. Farmers can’t just roam a 500-acre field picking rocks very well. They can pick some of the rocks and put a dent in it, but they’ll never know for sure how big the problem is or how well it’s been solved.

• Secondly, there’s got to be a better way to pick rocks. Traditional rock pickers are slow or very hard on the ground, so people opt to just pick their rocks by hand, says Thompson. The TerraClear team’s aim was to mimic the human way of picking rocks.

The tool suite they designed answered both questions: thorough field mapping for efficiency in tandem with robotic arm picking for individual rocks.

Picking it right

TerraClear touts that its robotic arm is both versatile and compatible.

It’s versatile because it can be used in any field condition.

“You’re not restrained to a bare soil, cultivated field,” says Thompson. “You can put it in a pastureland if you want. You can pick on a seeded field. You can pick on a disced field. You can pick in any condition that you’re comfortable getting the equipment out there.”

The compatibility angle was a highly sought-after design component. TerraClear’s team wanted their machinery to work for everybody and every piece of equipment possible.

“Everybody has a different skid steer,” Thompson says. “We put a lot of engineering into bypassing the controls. As long as you have the minimum power requirements on a skid steer – 18-gallon flow and 2,800-pound tipping capacity – you can really control it on any piece of equipment.”

But it’s not just for skid steers; tractors with front-end loaders and even backhoes can run the picker.

This picker is designed for the operator to selectively pick rocks, and it may not be as efficient as a drum-type picker would be in dense areas with smaller rocks. However, Thompson says it will pick in super-dense areas, the operator just needs to be aware of how quickly the bucket is filling.

“We’ve tried to windrow the rocks and run this thing, and you can fill the bucket up in like 90 seconds,” he notes.

The No. 1 question TerraClear team members are asked is how well do the tracks hold up?

Thompson’s answer: a lot longer than you would suppose.

“When we first put these tracks on there, I would have guessed they would last about an hour. We’ve actually only had one track rip, and it was a guy trying to dig a stump out,” he laughs. “Generally, it’s designed for rocks.”

Thompson says during R&D, the team has put 60,000-70,000 rocks through the test pickers and noticed the tracks start to wear on the outside but will still grab rocks. A replacement track comes in at $100, so it’s not generally cost-prohibitive to replace if needed.

Continuing the versatility conversation, the picker is designed to pick up rocks from 4 to 24 inches in size. Smaller rocks tend to fall through the tines on the bucket. Larger rocks – up to 30 inches – can be picked up but require a little more skill from the operator, explains Thompson.

He mentions that the trickiest rocks for any picker are flat rocks. The TerraClear picker can pick up flat rocks but their orientation may have to be changed for it to do so.

Making the picker work for everybody was critical. Thompson knows rock picking is typically thought of as the worst job on the farm, so the team designed the picker to be simple and fun to use.

“We really wanted to make it the first job or one of the more fun jobs on the farm, so kids are eager to do it, or folks who aren’t able to do a lot of the physical stuff can still get out and contribute to farming,” Thompson says.


The TerraClear rock picker is designed to be able to pick rocks under any field condition, giving farmers flexibility. Thompson says some farmers opt to pick in the spring, some in the fall, for differing reasons.

Obviously, skid steers offer one of the best field-of-vision options for the operator, but cause more ground disturbance than say a tractor would. Thus, timing may depend highly on the type of equipment to which the picker is mounted.

Most commonly, farmers wait until after harvest and before snow to get out and pick rocks.

Field mapping is currently done by a third party. In eastern Idaho, a Blackfoot company offers the service. Picking can also be outsourced.

TerraClear has crews in northern and southern Idaho and another crew in Minnesota who offer mapping and rock picking.

Pickers can be purchased now. The TerraClear rock picker has a $30,000 list price. Orders are being taken now for delivery in spring of 2022.

Contact Thompson with any questions at Visit TerraClear online at

(Paige Nelson is a freelance writer from Rigby)