How much does it cost to drill a well in Montana?

The main cost drivers

Well cost is not one number but a stack of them, and depth influences several at once.

• Depth. Drilling is generally priced per foot, so this is the largest variable — and the one you cannot know precisely in advance.
• Geology. Drilling unconsolidated sand and gravel is a different job from drilling hard bedrock. Rate of progress, bit wear, and method all change.
• Casing and completion. Deeper wells need more casing, and difficult formations may need more of it.
• Pump and equipment. The pump must be set below the water level, so a deep static water level means a larger pump, more wire, and a higher operating cost for the life of the well.
• Access and siting. Getting a rig to the site, and setback requirements from septic systems and property lines, can add cost or force a less convenient location.
• Whether you find water on the first attempt. This is the risk nobody likes to price.

Why the range matters more than the average

Consider a property where comparable nearby wells run from 120 to 400 feet. The average is not the useful number — the spread is, because the difference between the low and high outcome is a materially different budget and possibly a different decision about the property.

This is why our reports present an estimated likely range plus a wider band showing where 80% of comparable wells fall, rather than a single predicted depth. You should be budgeting against the range, and asking your driller what happens if the hole goes deeper than expected.

Costs beyond the borehole

Budget for the whole system, not just the drilling. Pump and pressure tank, wiring and controls, the water line to the house, any treatment the water turns out to need, and a laboratory test are all part of getting usable water to a tap.

There is also the regulatory step. Since 2023, a Notice of Intent must be filed with DNRC and authorized before drilling under the exempt-well provisions, and a Notice of Completion is due afterwards. Inside a controlled groundwater area or a closed basin, the path may involve a permit application instead, which is a different timeline and a different cost.

Getting bids that mean something

Talk to licensed drillers who work in the immediate area. They have drilled the wells around the property, and that local knowledge is worth more than any database — including ours.

Bring the comparable-well data with you. A driller who can see the recorded depths, yields, and lithology of nearby wells can give you a far more grounded estimate than one working from an address alone. That is precisely what our reports are for.