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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 September 2026 · Based on 45,508 public records from MBMG GWIC, Montana DNRC, Montana DEQ, EPA SEMS, EPA UST Finder

Wells on record

22,262

21,398 with recorded depth

Median well depth

193 ft

half of wells 103–300 ft

Median static water level

56 ft

19,425 measurements

Median tested yield

25 gpm

20,111 pump tests

Well depth

How deep are wells in Flathead County?

Of 21,398 wells with a recorded total depth, the median is 193 feet. Half were drilled between 103 and 300 feet; one in ten went deeper than 447 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

4,044 wells have been completed here since 2016, 336 of them in the last twelve months. The newest log on file was completed September 23, 2026. Records run back to 1877.

What the wells are for

  • Domestic18,922
  • Irrigation1,275
  • Stockwater1,189
  • Monitoring709
  • Public Water Supply707

How they were drilled

  • Rotary11,348
  • Cable2,663
  • Forward Rotary2,083
  • Air Rotary737

Drillers filing well logs in Flathead County

  • Billmayer Drilling518 since 2016 · 2026
  • Davis Brothers Drilling417 since 2016 · 2026
  • Glazier Drilling399 since 2016 · 2026
  • Coldwater Drilling And Pumps365 since 2016 · 2026
  • Chambers Drilling Company362 since 2016 · 2026
  • Oh Well Drilling And Pump347 since 2016 · 2026
  • Allwest Drilling Inc325 since 2016 · 2025
  • Rm Drilling And Well Services263 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 22,658 water rights in the county: 18,172 groundwater and 4,480 surface water, 20,747 of them active. The median priority date is 1989, and the oldest claim dates to 1855.

Types of right

  • Ground Water Certificate14,909
  • Statement Of Claim4,530
  • Provisional Permit1,982
  • Exempt Notice536
  • Converted Terminates482

Purposes

  • Domestic8,538
  • Domestic; Lawn And Garden3,790
  • Irrigation1,630
  • Domestic; Stock1,122
  • Stock988

DNRC basins

  • 76LJ19,661
  • 76K1,144
  • 76L756
  • 76I562
  • 76C204

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

256

50 open · 206 resolved

Superfund program sites

7

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.