Helena, Montana · Since 2013
Leader in underground trenchless technology
Horizontal directional drilling, plowing, trenching and hydro excavation for water, sewer, power, gas, telecom and fiber — plus hands-on consulting for drilling contractors from a Montana operator who has been boring since 2003.
What we do
Underground,
start to finish
Trenchless drilling lets us serve underground utilities — water, sewer, power, telecom and fiber — without tearing up roads, yards or traffic. Pick the method that fits the ground; we'll handle the rest.
HDD / Boring
Steerable bores under roads, creeks, driveways and landscaping — the surface stays intact.
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Cable Plowing
Vibratory plowing places cable and conduit at depth with little surface evidence.
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Trenching & Excavation
Open-cut trenching for multiple pipes, drainage and new-construction utilities.
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Hydro Excavation
Non-destructive digging to daylight utilities, pothole crossings and dig pole holes.
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Fiber Optic
Conduit, innerduct and drops for carriers, broadband builds and campuses.
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Coax / CATV
Underground cable-TV and broadband coax plant, pedestals and drops.
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Telephone / Copper
Underground telco plant, copper replacement and service drops.
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Power / Electrical
Distribution conduit, services, street lighting and pole holes for utilities.
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Water Lines
Water services, mains, well lines and irrigation — bored or trenched.
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Sewer Lines
Sewer laterals and lines bored or trenched, plus sewer and storm clean-out.
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Traffic Control
Flagging, lane closures, detours and compliant work zones.
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Telecom Construction
Turnkey underground telecom plant: bore, plow, trench, restore.
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Restoration
Small-scale concrete & asphalt repair and landscape clean-up and restoration.
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Consulting
Bore planning, bid help, troubleshooting and crew training.
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Talk it through with Beau
Describe the job and get a straight answer on method and cost.
(406) 521-0015Consulting
Two decades of drilling,
on call for your crew
Beau Straub has been boring since 2003, grew a Colorado telecom and drilling company to more than 100 employees, and built 406 Underground in Montana. Drilling companies still call him for help — now you can book that time directly.
Bore planning
Path, depth, tooling and crossings worked out before the rig shows up.
Bids & estimating
Footage, production rates and risk priced realistically.
Problem bores
Rock, cobble, lost returns, stuck tooling — a second set of eyes.
Crews & safety
Driller, locator and flagger training; JHA and safety programs.
Helena, MTMontana's turnkey drilling solution
Quality commercial boring at competitive prices
Based in Helena, 406 Underground (Four O Six Underground) specializes in telecommunications and horizontal directional drilling. We also provide hydro excavating, traffic control, small-scale asphalt and concrete, and landscape clean-up and restoration — so one call covers the whole underground scope.
- Turnkey or component. We can handle a particular piece or turnkey the entire project.
- Proactive locating. Utility crossings are located and potholed before the bore.
- Clean job sites. Spoils contained and removed; we work in as tight a space as safety permits.
- Safety first. Daily job hazard analysis, drug testing and driver's license checks.
- Free estimates after an inspection of the proposed project.
Utilities we install
If it goes underground,
we put it there
Water, sewer, power, gas and every kind of communications cable — bored, plowed or trenched to the owner's spec.
- Water
- Sewer
- Power
- Gas / steel
- Fiber
- Coax / CATV
- Telephone / copper
- Telecom
- Irrigation / poly
- Storm drain
What clients say
Trusted by Montana's
utilities and neighbors
From NorthWestern Energy project contacts to homeowners who needed a line under the road.
Four O Six Underground Inc., is my primary boring company when directional boring is required. They have addressed my needs time and again by completing the projects as requested. The word no is not on their vocabulary and they strive to accommodate the customer 100 percent.
The crews not only provide accurate bores, but also take responsibility for their actions and clean up after themselves without being asked when leaving a jobsite. Four O Six is also proactive in locating utility crossings… Montana owned and operated, this company has a family touch to it and it shows in their desire to do a good job at a minimal cost.
I was without potable water until Four O Six Underground quickly, professionally drilled horizontally under the road to connect new wires from the well to my home! Excellent customer service and quality work! Thanks!
Best directional drilling company in Montana! 5 star service!
Testimonials as published on our previous website and public Google reviews. See us on Google Maps →
From the field
406 Underground at work
Photos from our own job sites and equipment.
Service area
Montana statewide — and beyond
Based in Helena and working across Montana, with projects in Wyoming, Idaho, North and South Dakota, Colorado and New Mexico.
Got a bore, a route or a problem job?
Call Beau directly — or send the details and he'll get back to you.