Montana water data · County
Prairie County: well depth, groundwater and water rights
What the public record says about water in Prairie 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 5,000 public records from MBMG GWIC, Montana DNRC, Montana DEQ, EPA UST Finder
Wells on record
1,778
1,652 with recorded depth
Median well depth
148 ft
half of wells 65–300 ft
Median static water level
63 ft
1,066 measurements
Median tested yield
10 gpm
1,366 pump tests
Well depth
How deep are wells in Prairie County?
Of 1,652 wells with a recorded total depth, the median is 148 feet. Half were drilled between 65 and 300 feet; one in ten went deeper than 800 feet and one in ten found water shallower than 26 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
63 ft
median depth to water at rest · half between 22 and 120 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 5 and 15 gpm
20% of tested wells produced under 5 gallons per minute and 22% 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 Prairie County
131 wells have been completed here since 2016, 2 of them in the last twelve months. The newest log on file was completed April 7, 2026. Records run back to 1891.
What the wells are for
- Stockwater1,336
- Domestic449
- Monitoring83
- Unused79
- Irrigation43
How they were drilled
- Rotary470
- Cable140
- Cable Tool112
- Forward Rotary79
Drillers filing well logs in Prairie County
- Sharp Drilling Inc37 since 2016 · 2025
- Askin Drilling31 since 2016 · 2025
- Higgins Drilling Company21 since 2016 · 2024
- Pirtz Waterworx Llc18 since 2016 · 2026
- H & H Drilling17 since 2016 · 2024
- West Central Environmental Consultants5 since 2016 · 2024
- Wahl Construction3 since 2016 · 2024
- Haz Tech Drilling Inc2 since 2016 · 2016
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 Prairie County
Montana DNRC lists 3,181 water rights in the county: 1,662 groundwater and 1,519 surface water, 3,017 of them active. The median priority date is 1958, and the oldest claim dates to 1864.
Types of right
- Statement Of Claim2,233
- Ground Water Certificate598
- Powder River Declaration154
- Provisional Permit122
- Exempt Notice26
Purposes
- Stock1,898
- Wildlife470
- Irrigation324
- Domestic187
- Domestic; Stock52
DNRC basins
- 42M1,870
- 42L524
- 42J188
- 40P186
- 42K154
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 Prairie 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.
- Fort Union Formation375 wells · 30% · median 150 ft
- Tongue River Member (of Ft Union Fm.)309 wells · 25% · median 106 ft
- Fox Hills-hell Creek Aquifer218 wells · 17% · median 800 ft
- Alluvium (quaternary)186 wells · 15% · median 27 ft
- Hell Creek Formation55 wells · 4% · median 565 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 Prairie County
Petroleum releases
20
5 open · 15 resolved
Superfund program sites
0
none on the National Priorities List
Registered tank facilities
21
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 2013. A property report screens the sites within a quarter, half and one mile of a specific parcel and links the agency records.