Montana water data · County
Big Horn County: well depth, groundwater and water rights
What the public record says about water in Big Horn 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 11,207 public records from MBMG GWIC, Montana DNRC, Montana DEQ, EPA SEMS, EPA UST Finder
Wells on record
3,849
3,449 with recorded depth
Median well depth
67 ft
half of wells 32–175 ft
Median static water level
25 ft
2,688 measurements
Median tested yield
12 gpm
2,403 pump tests
Well depth
How deep are wells in Big Horn County?
Of 3,449 wells with a recorded total depth, the median is 67 feet. Half were drilled between 32 and 175 feet; one in ten went deeper than 320 feet and one in ten found water shallower than 20 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
25 ft
median depth to water at rest · half between 12 and 74 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
12 gpm
median tested yield · half between 5 and 22 gpm
18% of tested wells produced under 5 gallons per minute and 36% 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 Big Horn County
221 wells have been completed here since 2016, 23 of them in the last twelve months. The newest log on file was completed July 24, 2026. Records run back to 1897.
What the wells are for
- Stockwater1,250
- Domestic1,071
- Monitoring753
- Research202
- Irrigation149
How they were drilled
- Rotary1,077
- Unknown524
- Cable401
- Forward Rotary271
Drillers filing well logs in Big Horn County
- American Drilling & Supply59 since 2016 · 2025
- Gary's Drilling Inc.42 since 2016 · 2026
- Bertram Drilling Inc24 since 2016 · 2025
- Haz Tech Drilling Inc16 since 2016 · 2020
- Higgins Drilling Company14 since 2016 · 2026
- A-1 Drilling11 since 2016 · 2024
- Wwc Engineering10 since 2016 · 2025
- Pioneer Technical Services Inc9 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 Big Horn County
Montana DNRC lists 7,140 water rights in the county: 2,554 groundwater and 4,569 surface water, 5,311 of them active. The median priority date is 1940, and the oldest claim dates to 1864.
Types of right
- Statement Of Claim3,958
- Reserved Claim1,593
- Ground Water Certificate1,204
- Provisional Permit166
- Stockwater Permit94
Purposes
- Stock4,930
- Irrigation943
- Domestic493
- Multiple Domestic190
- Domestic; Stock130
DNRC basins
- 43P2,711
- 43O1,590
- 42B1,417
- 42A518
- 42KJ471
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 Big Horn 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.
- Tongue River Member (of Ft Union Fm.)643 wells · 35% · median 145 ft
- Alluvium (quaternary)242 wells · 13% · median 30 ft
- Terrace Deposits (quaternary)224 wells · 12% · median 28 ft
- Tullock Member (of Ft Union Fm.)98 wells · 5% · median 100 ft
- Fort Union Formation70 wells · 4% · median 237 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 Big Horn County
Petroleum releases
81
19 open · 62 resolved
Superfund program sites
2
none on the National Priorities List
Registered tank facilities
135
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 2019. A property report screens the sites within a quarter, half and one mile of a specific parcel and links the agency records.