Montana water data · County
Granite County: well depth, groundwater and water rights
What the public record says about water in Granite 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 6,762 public records from MBMG GWIC, Montana DNRC, Montana DEQ, EPA SEMS, EPA UST Finder
Wells on record
2,444
2,389 with recorded depth
Median well depth
80 ft
half of wells 45–180 ft
Median static water level
30 ft
2,093 measurements
Median tested yield
20 gpm
2,133 pump tests
Well depth
How deep are wells in Granite County?
Of 2,389 wells with a recorded total depth, the median is 80 feet. Half were drilled between 45 and 180 feet; one in ten went deeper than 340 feet and one in ten found water shallower than 28 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.
Static water level
30 ft
median depth to water at rest · half between 15 and 75 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
20 gpm
median tested yield · half between 12 and 30 gpm
4% of tested wells produced under 5 gallons per minute and 55% 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 Granite County
523 wells have been completed here since 2016, 49 of them in the last twelve months. The newest log on file was completed September 6, 2026. Records run back to 1870.
What the wells are for
- Domestic1,958
- Stockwater198
- Other100
- Monitoring84
- Irrigation71
How they were drilled
- Rotary998
- Forward Rotary171
- Dual Rotary149
- Cable147
Drillers filing well logs in Granite County
- Okeefe Drilling Co243 since 2016 · 2026
- Jeromes Drilling Co95 since 2016 · 2025
- Ak Drilling Inc51 since 2016 · 2026
- Western Water Wells19 since 2016 · 2025
- Ak Drilling, Inc.19 since 2016 · 2022
- Western Montana Drilling Co.15 since 2016 · 2026
- Heimark Drilling12 since 2016 · 2026
- Aquasource Drilling Llc8 since 2016 · 2024
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 Granite County
Montana DNRC lists 4,258 water rights in the county: 2,217 groundwater and 2,041 surface water, 3,798 of them active. The median priority date is 1950, and the oldest claim dates to 1850.
Types of right
- Statement Of Claim2,568
- Ground Water Certificate1,406
- Exempt Notice100
- Provisional Permit95
- Unused Adjudication Number30
Purposes
- Stock1,312
- Domestic956
- Irrigation858
- Domestic; Lawn And Garden279
- Mining167
DNRC basins
- 76GJ2,116
- 76E1,191
- 76G892
- 76F59
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 Granite 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.
- Sand And Gravel (pleistocene)281 wells · 18% · median 58 ft
- Middle Belt Carbonate254 wells · 16% · median 160 ft
- Sediments (tertiary)252 wells · 16% · median 120 ft
- Sand And Gravel (holocene)242 wells · 16% · median 38 ft
- Quaternary Undifferentiated103 wells · 7% · median 35 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 Granite County
Petroleum releases
22
2 open · 20 resolved
Superfund program sites
3
none on the National Priorities List
Registered tank facilities
35
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 2007. A property report screens the sites within a quarter, half and one mile of a specific parcel and links the agency records.