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Montana water data · County

Lake County: well depth, groundwater and water rights

What the public record says about water in Lake 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 22,362 public records from MBMG GWIC, Montana DNRC, Montana DEQ, EPA SEMS, EPA UST Finder

Wells on record

8,298

7,938 with recorded depth

Median well depth

180 ft

half of wells 98–325 ft

Median static water level

50 ft

6,914 measurements

Median tested yield

25 gpm

7,268 pump tests

Well depth

How deep are wells in Lake County?

Of 7,938 wells with a recorded total depth, the median is 180 feet. Half were drilled between 98 and 325 feet; one in ten went deeper than 480 feet and one in ten found water shallower than 45 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
11%
50–100 ft
15%
100–200 ft
28%
200–300 ft
17%
300–500 ft
20%
500 ft and deeper
9%

Static water level

50 ft

median depth to water at rest · half between 22 and 103 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 50 gpm

4% of tested wells produced under 5 gallons per minute and 64% 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 Lake County

1,338 wells have been completed here since 2016, 97 of them in the last twelve months. The newest log on file was completed October 15, 2026. Records run back to 1870.

What the wells are for

  • Domestic6,865
  • Stockwater1,153
  • Irrigation1,033
  • Monitoring442
  • Public Water Supply237

How they were drilled

  • Rotary4,060
  • Forward Rotary863
  • Cable669
  • Air Rotary267

Drillers filing well logs in Lake County

  • Ace Drilling367 since 2016 · 2026
  • Oh Well Drilling And Pump241 since 2016 · 2026
  • Allwest Drilling Inc193 since 2016 · 2025
  • Coldwater Drilling And Pumps81 since 2016 · 2026
  • Billmayer Drilling64 since 2016 · 2026
  • Jeromes Drilling Co59 since 2016 · 2025
  • Oh Well Drilling & Pump52 since 2016 · 2018
  • West Central Environmental Consultants35 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 Lake County

Montana DNRC lists 13,701 water rights in the county: 9,433 groundwater and 4,029 surface water, 10,135 of them active. The median priority date is 1978, and the oldest claim dates to 1850.

Types of right

  • Statement Of Claim4,481
  • Ground Water Certificate3,542
  • Registration Certificate2,387
  • Cskt Registration Certificate1,083
  • Domestic Allowance686

Purposes

  • Domestic4,593
  • Stock1,417
  • Irrigation1,368
  • Domestic; Lawn And Garden1,192
  • Multiple Domestic693

DNRC basins

  • 76L6,883
  • 76LJ5,575
  • 76K1,241
  • 76M2

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 Lake 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.

  • Glacial Lake Missoula Beds957 wells · 21% · median 128 ft
  • Alluvium (pleistocene)811 wells · 18% · median 200 ft
  • Ravalli Group804 wells · 17% · median 243 ft
  • Glacial Drift654 wells · 14% · median 120 ft
  • Glacial Outwash (pleistocene)442 wells · 10% · median 57 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 Lake County

Petroleum releases

140

23 open · 117 resolved

Superfund program sites

7

none on the National Priorities List

Registered tank facilities

216

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 2024. A property report screens the sites within a quarter, half and one mile of a specific parcel and links the agency records.