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Montana water data · County

Flathead County: well depth, groundwater and water rights

What the public record says about water in Flathead County: how deep wells go, where the water table sits, what wells produce, which water rights are on file, and which documented environmental sites are nearby. Area statistics orient you; a property report analyzes the records around one specific parcel.

Updated November 2026 · Based on 45,656 public records from MBMG GWIC, Montana DNRC, Montana DEQ, EPA SEMS, EPA UST Finder

Wells on record

22,315

21,451 with recorded depth

Median well depth

193 ft

half of wells 104–300 ft

Median static water level

56 ft

19,476 measurements

Median tested yield

25 gpm

20,164 pump tests

Well depth

How deep are wells in Flathead County?

Of 21,451 wells with a recorded total depth, the median is 193 feet. Half were drilled between 104 and 300 feet; one in ten went deeper than 448 feet and one in ten found water shallower than 30 feet. Depth is set by local geology and position on the landscape, both of which change over short distances, so the spread matters as much as the median.

under 50 ft
15%
50–100 ft
9%
100–200 ft
28%
200–300 ft
23%
300–500 ft
17%
500 ft and deeper
8%

Static water level

56 ft

median depth to water at rest · half between 20 and 105 ft

The static level is how far below ground the water stands before pumping, measured by the driller at completion. It affects pump setting and operating cost, and it moves with season and with neighbouring use.

Well yield

25 gpm

median tested yield · half between 15 and 45 gpm

4% of tested wells produced under 5 gallons per minute and 67% produced 20 or more. These are short completion tests, not sustained-capacity tests; a household typically needs 3 to 5 gpm with storage.

Drilling activity

Recent well drilling in Flathead County

4,096 wells have been completed here since 2016, 328 of them in the last twelve months. The newest log on file was completed October 20, 2026. Records run back to 1877.

What the wells are for

  • Domestic18,973
  • Irrigation1,278
  • Stockwater1,189
  • Monitoring709
  • Public Water Supply708

How they were drilled

  • Rotary11,383
  • Cable2,663
  • Forward Rotary2,083
  • Air Rotary737

Drillers filing well logs in Flathead County

  • Billmayer Drilling518 since 2016 · 2026
  • Davis Brothers Drilling427 since 2016 · 2026
  • Glazier Drilling400 since 2016 · 2026
  • Coldwater Drilling And Pumps380 since 2016 · 2026
  • Chambers Drilling Company366 since 2016 · 2026
  • Oh Well Drilling And Pump347 since 2016 · 2026
  • Allwest Drilling Inc325 since 2016 · 2025
  • Rm Drilling And Well Services266 since 2016 · 2026

Ranked by well logs filed with GWIC, public record only. Not an endorsement, a referral or a paid listing; we have no business relationship with these companies. Verify licensing with the Montana Board of Water Well Contractors before hiring.

Water rights

Water rights on file in Flathead County

Montana DNRC lists 22,747 water rights in the county: 18,263 groundwater and 4,478 surface water, 20,749 of them active. The median priority date is 1989, and the oldest claim dates to 1855.

Types of right

  • Ground Water Certificate14,990
  • Statement Of Claim4,528
  • Provisional Permit1,986
  • Exempt Notice536
  • Converted Terminates482

Purposes

  • Domestic8,548
  • Domestic; Lawn And Garden3,814
  • Irrigation1,631
  • Domestic; Stock1,122
  • Stock988

DNRC basins

  • 76LJ19,743
  • 76K1,145
  • 76L762
  • 76I563
  • 76C203

Area totals describe the neighbourhood, not any one parcel. Montana publishes no authoritative link between a parcel and a water right; whether a right attaches to a specific property is a property-level question that our reports answer with the DNRC abstract linked.

Aquifers and geology

What wells in Flathead County draw from

Drillers record the aquifer a well is completed in. The units below account for the wells here that carry an aquifer assignment; the median depth beside each is for wells completed in that unit.

  • Alluvium (pleistocene)4,077 wells · 35% · median 191 ft
  • Alluvium (holocene)2,242 wells · 19% · median 26 ft
  • Glacial Drift1,788 wells · 15% · median 128 ft
  • Middle Belt Carbonate1,050 wells · 9% · median 257 ft
  • Ravalli Group1,000 wells · 8% · median 248 ft

Aquifer assignments are the driller's, recorded at completion, and many older logs carry none. Absence of an assignment is not evidence about the geology.

Environmental groundwater screening

Documented environmental sites in Flathead County

Petroleum releases

257

51 open · 206 resolved

Superfund program sites

12

1 on or proposed for the NPL

Registered tank facilities

325

underground storage tanks, current and historical

A documented release or site in the area is not evidence that any particular well is affected. Whether a release reaches a well depends on groundwater flow direction, geology, well depth and construction, the extent of the plume and the cleanup performed. The most recent release reported here dates to 2026. A property report screens the sites within a quarter, half and one mile of a specific parcel and links the agency records.