Big Sky: well depth, groundwater and water rights

Well depth

How deep are wells in Big Sky?

Of 988 wells with a recorded total depth, the median is 230 feet. Half were drilled between 100 and 449 feet; one in ten went deeper than 697 feet and one in ten found water shallower than 44 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.

Drilling activity

Recent well drilling in Big Sky

220 wells have been completed here since 2016, 13 of them in the last twelve months. The newest log on file was completed July 22, 2026. Records run back to 1931.

Water rights

Water rights on file in Big Sky

Montana DNRC lists 717 water rights with a point of diversion inside this area: 650 groundwater and 67 surface water, 612 of them active. The median priority date is 2006, and the oldest claim dates to 1862.

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 Sky 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.

• Frontier Formation57 wells · 20% · median 224 ft
• Sand And Gravel (quaternary)49 wells · 17% · median 31 ft
• Kootenai Formation37 wells · 13% · median 312 ft
• Muddy Sandstone Member (of Thermopolis Shale)29 wells · 10% · median 290 ft
• Mowry Shale (of Colorado Group)27 wells · 10% · median 307 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 Sky

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 2021. A property report screens the sites within a quarter, half and one mile of a specific parcel and links the agency records.