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Montana water data · Community in Madison County

McAllister: well depth, groundwater and water rights

What the public record says about water in McAllister: 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 309 public records from MBMG GWIC, Montana DNRC, Montana DEQ, EPA UST Finder, US Census (place boundary)

Wells on record

160

70.5 per sq mi

Median well depth

60 ft

half of wells 40–100 ft

Median static water level

20 ft

148 measurements

Median tested yield

25 gpm

146 pump tests

Well depth

How deep are wells in McAllister?

Of 157 wells with a recorded total depth, the median is 60 feet. Half were drilled between 40 and 100 feet; one in ten went deeper than 167 feet and one in ten found water shallower than 30 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
40%
50–100 ft
32%
100–200 ft
20%
200–300 ft
6%
300–500 ft
1%
500 ft and deeper
0%

Static water level

20 ft

median depth to water at rest · half between 15 and 36 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 20 and 40 gpm

1% of tested wells produced under 5 gallons per minute and 77% 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 McAllister

35 wells have been completed here since 2016, 1 of them in the last twelve months. The newest log on file was completed October 9, 2025. Records run back to 1900.

What the wells are for

  • Domestic129
  • Stockwater17
  • Irrigation14
  • Monitoring5
  • Public Water Supply2

How they were drilled

  • Rotary87
  • Dual Rotary22
  • Cable13
  • Forward Rotary6

Drillers filing well logs in McAllister

  • Graham Drilling Inc22 since 2016 · 2025
  • Red Tiger Drilling4 since 2016 · 2023
  • Van Dyken Drilling Inc3 since 2016 · 2023
  • Potts Drilling Inc3 since 2016 · 2021
  • Madison Drilling & Pump Supply37 all-time · 2009
  • Okeefe Drilling Co10 all-time · 2000
  • Hillman Drilling4 all-time · 1986
  • Big Sky4 all-time · 1999

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 McAllister

Montana DNRC lists 146 water rights with a point of diversion inside this area: 127 groundwater and 19 surface water, 135 of them active. The median priority date is 1998, and the oldest claim dates to 1866.

Types of right

  • Ground Water Certificate116
  • Statement Of Claim22
  • Provisional Permit5
  • Exempt Notice3

Purposes

  • Domestic59
  • Domestic; Lawn And Garden35
  • Irrigation13
  • Stock10
  • Lawn And Garden; Domestic5

DNRC basins

  • 41F146

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 McAllister 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)5 wells · 63% · median 65 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 McAllister

Petroleum releases

1

0 open · 1 resolved

Superfund program sites

0

none on the National Priorities List

Registered tank facilities

2

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 1998. A property report screens the sites within a quarter, half and one mile of a specific parcel and links the agency records.