Montana water data · County

Carter County: well depth, groundwater and water rights

What the public record says about water in Carter 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 11,415 public records from MBMG GWIC, Montana DNRC, Montana DEQ, EPA UST Finder

Wells on record

1,630

1,507 with recorded depth

Median well depth

160 ft

half of wells 80–274 ft

Median static water level

65 ft

1,385 measurements

Median tested yield

10 gpm

1,495 pump tests

Well depth

How deep are wells in Carter County?

Of 1,507 wells with a recorded total depth, the median is 160 feet. Half were drilled between 80 and 274 feet; one in ten went deeper than 460 feet and one in ten found water shallower than 31 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
16%
50–100 ft
13%
100–200 ft
29%
200–300 ft
18%
300–500 ft
15%
500 ft and deeper
8%

Static water level

65 ft

median depth to water at rest · half between 29 and 136 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

10 gpm

median tested yield · half between 6 and 20 gpm

12% of tested wells produced under 5 gallons per minute and 26% 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 Carter County

164 wells have been completed here since 2016, 6 of them in the last twelve months. The newest log on file was completed July 29, 2026. Records run back to 1869.

What the wells are for

  • Stockwater1,345
  • Domestic383
  • Monitoring31
  • Irrigation26
  • Public Water Supply15

How they were drilled

  • Rotary778
  • Forward Rotary139
  • Drilled43
  • Unknown21

Drillers filing well logs in Carter County

  • Askin Drilling104 since 2016 · 2025
  • Water System Drilling Inc19 since 2016 · 2018
  • Higgins Drilling Company11 since 2016 · 2024
  • Ww Drilling Llc10 since 2016 · 2026
  • Hansen Environmental Drilling6 since 2016 · 2025
  • Weston Engineering, Inc.5 since 2016 · 2020
  • Keller Drilling5 since 2016 · 2026
  • Olympus Technical Services4 since 2016 · 2022

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 Carter County

Montana DNRC lists 9,754 water rights in the county: 2,344 groundwater and 7,410 surface water, 9,422 of them active. The median priority date is 1952, and the oldest claim dates to 1862.

Types of right

  • Statement Of Claim6,879
  • Powder River Declaration1,070
  • Ground Water Certificate824
  • Stockwater Permit678
  • Provisional Permit264

Purposes

  • Stock7,284
  • Irrigation1,134
  • Wildlife618
  • Domestic238
  • Domestic; Stock137

DNRC basins

  • 39F3,783
  • 39E3,193
  • 42J945
  • 39FJ704
  • 42L532

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 Carter 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.

  • Fox Hills-hell Creek Aquifer498 wells · 43% · median 240 ft
  • Hell Creek Formation333 wells · 29% · median 160 ft
  • Alluvium (quaternary)108 wells · 9% · median 30 ft
  • Fox Hills Formation Or Sandstone88 wells · 8% · median 160 ft
  • Ludlow Member (of Ft Union Fm.)70 wells · 6% · median 158 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 Carter County

Petroleum releases

12

6 open · 6 resolved

Superfund program sites

0

none on the National Priorities List

Registered tank facilities

19

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 2010. A property report screens the sites within a quarter, half and one mile of a specific parcel and links the agency records.