Why does water hardness vary across Montana?

Water hardness varies across Montana because utilities can use different groundwater wells, reservoirs, treatment plants, blends, and distribution zones. Private wells can also differ from nearby municipal water.

What city in Montana has the hardest water?

Miles City has the hardest water among higher-confidence Montana city pages at 231 PPM. Check the city page for local systems and ZIP codes before making treatment decisions.

Does this include municipal water, well water, or both?

The state report combines public water system records, utility reports, and USGS monitoring where available. Municipal treated-water records are preferred when present. Private well hardness can vary at the address level and should be confirmed with a local test.

How many water systems are in Montana?

Montana has 792 active community water systems serving 335 cities.

Water Hardness in Montana

Average: 260 PPMVery Hard335 cities792 water systems

State report

Is Montana Water Hard or Soft?

Montana water is very hard on average at 260 PPM (15.2 GPG). Local readings can vary by utility, aquifer, treatment plant, and private well use.

State average

260 PPM

Very Hard

Local coverage

335 cities

792 water systems

Source profile

194 ZIPs

direct or USGS-backed

Montana has mixed source coverage across treated-water records, USGS monitoring, and estimated fallback values.

Methodology Data sources Search by ZIP code

State data profile

How to read the Montana results

State pages are screening and comparison hubs. They summarize ZIP, city, and water-system patterns so you can find the local page that best matches your home or utility.

Direct or USGS-backed ZIPs

194 of 346

56% use treated-water records or USGS monitoring.

Estimated ZIP values

151 ZIPs

44% use nearby, county, or state-level fallback values.

Dataset update

March 9, 2026

Source coverage and rollups are rebuilt from the public dataset.

Use the source coverage below to judge how much local confirmation a specific city or ZIP needs. The methodology page explains the source hierarchy, weighting, and limitations.

State Average

260 PPM

Very Hard

Coverage

335 cities

792 water systems in the state rollup.

Data Source Coverage

ZIP-level source mix for Montana; higher direct and USGS coverage means less reliance on regional estimates.

346 ZIPs covered

Verified treated water

Utility, CCR, or state treated-water records

41%

142 ZIPs

High-confidence USGS

Environmental monitoring matched to local systems

15%

52 ZIPs

Estimated

Nearby, county, or state-level fallback values

44%

151 ZIPs

1 ZIPs have insufficient source data and are excluded from search sitemaps.

In Montana, 41% of ZIPs use verified treated-water records, 15% use high-confidence USGS monitoring, and 44% use estimates that should be confirmed locally for treatment decisions.

What the Data Shows in Montana

Hard water is common but not universal in Montana: 50% of classified ZIPs are hard or very hard.

Montana uses a mixed data profile across treated-water records, USGS monitoring, and estimated fallback values.

Use the city table below to compare local results. For estimated locations or unusually high readings, confirm with your utility or a home hardness test before sizing treatment equipment.

ZIP Hardness Distribution

Soft4% (15)

Slightly Hard18% (61)

Moderately Hard28% (97)

Hard19% (67)

Very Hard30% (105)

Treatment Takeaway

For many homes in Montana, hardness is high enough that scale buildup, fixture spotting, and appliance wear are realistic concerns. A local test is the best starting point before sizing a softener.

How to Use This Data

Use the source coverage above to decide how much local confirmation you need for a specific city or ZIP code.

Source-Backed Water Systems in Montana

Large systems with treated-water reports or USGS monitoring behind the state rollup.

Review source labels

Water system	Hardness	Source label	Population
Missoula Water MT0000294 - Missoula County	176 PPM Moderately Hard	Annual Water Quality Report Verified - Annual Water Quality Report	68,200
Westview Mobile Home Park MT0000437 - Missoula County	176 PPM Moderately Hard	Annual Water Quality Report Verified - Annual Water Quality Report	947
Phantom Hills Water System MT0004379 - Missoula County	176 PPM Moderately Hard	Annual Water Quality Report Verified - Annual Water Quality Report	810
Travois Village Mobile Park MT0003909 - Missoula County	176 PPM Moderately Hard	Annual Water Quality Report Verified - Annual Water Quality Report	702
Greenfield Mobile Home Park MT0000373 - Missoula County	176 PPM Moderately Hard	Annual Water Quality Report Verified - Annual Water Quality Report	620
Wye Area Water System MT0004107 - Missoula County	176 PPM Moderately Hard	Annual Water Quality Report Verified - Annual Water Quality Report	512
Grant Creek Water Users Association Inc MT0003305 - Missoula County	176 PPM Moderately Hard	Annual Water Quality Report Verified - Annual Water Quality Report	380
Katoonah Lodges MT0003692 - Missoula County	176 PPM Moderately Hard	Annual Water Quality Report Verified - Annual Water Quality Report	258

Useful Montana City Pages

Shortcuts to city pages backed by more ZIP-code or water-system data.

Cities With More Local Data

Missoula

5 ZIPs · 51 systems

Moderately Hard (176 PPM)

Billings

3 ZIPs · 36 systems

Moderately Hard (150 PPM)

Great Falls

3 ZIPs · 18 systems

Moderately Hard (120 PPM)

Helena

2 ZIPs · 24 systems

Slightly Hard (80 PPM)

Manhattan

2 ZIPs · 16 systems

Slightly Hard (105 PPM)

Kalispell

1 ZIP · 25 systems

Slightly Hard (100 PPM)

Prioritize cities with multiple ZIPs and systems, then use source badges on each city page to separate verified treated-water records from estimates.

Top 10 Hardest Water Cities

#	City	Hardness
1	Miles City	Hard (231 PPM)
2	Polson	Hard (205 PPM)
3	Montana City	Hard (195 PPM)
4	Laurel	Hard (181 PPM)
5	Lolo	Moderately Hard (178 PPM)
6	Missoula	Moderately Hard (176 PPM)
7	Frenchtown	Moderately Hard (175 PPM)
8	Billings Heights	Moderately Hard (152 PPM)
9	Billings	Moderately Hard (150 PPM)
10	Great Falls	Moderately Hard (120 PPM)

Top 10 Softest Water Cities

#	City	Hardness
1	Helena	Slightly Hard (80 PPM)
2	East Helena	Slightly Hard (86 PPM)
3	West Yellowstone	Slightly Hard (92 PPM)
4	Columbia Falls	Slightly Hard (96 PPM)
5	Libby	Slightly Hard (97 PPM)
6	Big Sky	Slightly Hard (99 PPM)
7	Bozeman	Slightly Hard (100 PPM)
8	Kalispell	Slightly Hard (100 PPM)
9	West Glacier	Slightly Hard (103 PPM)
10	Manhattan	Slightly Hard (105 PPM)

All Cities in Montana

City pages marked Estimated use fallback values and should be confirmed with local testing or utility data.

AbsarokeeVery Hard ActonModerately Hard AlbertonModerately Hard AlderVery Hard AlzadaVery Hard AnacondaHard AntelopeVery Hard ArleeModerately Hard AshlandVery Hard AugustaSlightly Hard AvonModerately Hard BabbSlightly Hard BainvilleHard BakerVery Hard BallantineModerately Hard BasinSlightly Hard BearcreekModerately Hard BelfryVery Hard BelgradeSlightly Hard Belle CreekVery Hard BeltModerately Hard BiddleHard Big ArmModerately Hard Big SandyVery Hard Big SkySlightly Hard Big TimberSlightly Hard BighornModerately Hard BillingsModerately Hard Billings HeightsModerately Hard BirneyHard Black EagleModerately Hard BloomfieldHard BonnerModerately Hard BoulderModerately Hard Box ElderVery Hard BoydModerately Hard BozemanSlightly Hard BradyVery Hard BridgerVery Hard BroadviewModerately Hard BrocktonVery Hard BrockwayHard BrusettHard BusbyModerately Hard ButteSoft BynumVery Hard CameronSlightly Hard Canyon CreekSlightly Hard CardwellSlightly Hard CarterVery Hard CascadeModerately Hard ChesterVery Hard ChinookVery Hard ChoteauModerately Hard CircleSoft ClintonModerately Hard Clyde ParkHard Coffee CreekVery Hard CohagenHard ColstripVery Hard Columbia FallsSlightly Hard ColumbusVery Hard CondonModerately Hard ConnerModerately Hard ConradVery Hard Cooke CityModerately Hard CoramSlightly Hard CorvallisSoft CraneVery Hard Crow AgencyModerately Hard CulbertsonHard CusterModerately Hard Cut BankModerately Hard DagmarVery Hard DarbyHard DaytonModerately Hard DeckerVery Hard Deer LodgeVery Hard DentonVery Hard DillonModerately Hard DivideSoft DixonModerately Hard DodsonVery Hard DrummondModerately Hard DupuyerHard DuttonVery Hard East Glacier ParSlightly Hard East HelenaSlightly Hard EdgarModerately Hard EkalakaVery Hard EllistonSoft ElmoModerately Hard EmigrantModerately Hard EnnisSlightly Hard EssexSlightly Hard EurekaModerately Hard FairfieldModerately Hard FairviewVery Hard FallonHard FishtailModerately Hard FlaxvilleHard FlorenceSlightly Hard FlowereeSlightly Hard ForestgroveModerately Hard ForsythVery Hard Fort BentonVery Hard Fort HarrisonSlightly Hard Fort PeckHard Fort ShawModerately Hard FortineHard FrenchtownModerately Hard FroidHard FrombergVery Hard GalataVery Hard Gallatin GatewaySlightly Hard GardinerModerately Hard GarrisonModerately Hard GarryowenModerately Hard GeraldineHard GeyserHard GildfordVery Hard GlasgowHard GlendiveVery Hard Gold CreekModerately Hard Grass RangeVery Hard Great FallsModerately Hard GreycliffVery Hard HallModerately Hard HamiltonHard HammondVery Hard HardinVery Hard HarlemVery Hard HarlowtonHard HarrisonSlightly Hard HathawayHard HauganHard HavreVery Hard HaysVery Hard Heart ButteHard HelenaSlightly Hard HelmvilleModerately Hard HeronSoft HighwoodHard HilgerVery Hard HinghamVery Hard HinsdaleVery Hard HogelandVery Hard HomesteadVery Hard Hot SpringsHard Hungry HorseSlightly Hard HuntleyModerately Hard HusonModerately Hard HyshamVery Hard IngomarModerately Hard InvernessVery Hard IsmayHard JacksonModerately Hard Jefferson CitySlightly Hard JoplinVery Hard JordanVery Hard Judith GapVery Hard KalispellSlightly Hard KevinVery Hard KilaSlightly Hard KinseyHard KremlinVery Hard LakesideSlightly Hard LambertSoft Lame DeerHard LarslanHard LaurelHard LavinaModerately Hard LedgerVery Hard LewistownVery Hard LibbySlightly Hard LimaVery Hard LincolnSlightly Hard LindsayHard LivingstonModerately Hard LloydVery Hard Lodge GrassVery Hard LoloModerately Hard LomaVery Hard LonepineModerately Hard LoringVery Hard LustreHard MaltaVery Hard ManhattanSlightly Hard MarionSlightly Hard Martin CitySlightly Hard MartinsdaleHard MarysvilleSlightly Hard Mc AllisterSlightly Hard Mc LeodSlightly Hard Medicine LakeHard MelroseSoft MelstoneVery Hard MelvilleVery Hard Miles CityHard MilltownModerately Hard MissoulaModerately Hard MoccasinVery Hard MoieseHard MoltModerately Hard MonarchModerately Hard Montana CityHard MooreVery Hard MosbyModerately Hard MusselshellHard NashuaVery Hard NeihartModerately Hard NorrisSlightly Hard NoxonSoft NyeSlightly Hard OilmontVery Hard OliveHard OlneySlightly Hard OpheimVery Hard OtterHard OutlookVery Hard OvandoModerately Hard PabloHard Park CityModerately Hard PeerlessHard PendroyHard PhilipsburgSlightly Hard PinesdaleSoft PlainsHard PlentywoodHard PlevnaVery Hard PolarisSoft PolebridgeSlightly Hard PolsonHard Pompeys PillarModerately Hard PonySlightly Hard PoplarVery Hard PowerVery Hard PrayModerately Hard ProctorModerately Hard PryorModerately Hard RamsaySoft RapeljeVery Hard RaynesfordSlightly Hard Red LodgeVery Hard RedstoneVery Hard ReedpointModerately Hard ReserveVery Hard RexfordModerately Hard RicheyVery Hard RichlandHard RinglingSlightly Hard RobertsVery Hard RollinsHard RonanSlightly Hard RoscoeModerately Hard RosebudHard RoundupVery Hard RoyVery Hard RudyardVery Hard RyegateVery Hard SacoVery Hard Saint IgnatiusHard Saint MarieHard Saint MarySlightly Hard Saint RegisModerately Hard Saint XavierModerately Hard SalteseSlightly Hard Sand CouleeModerately Hard Sand SpringsHard SandersModerately Hard SavageVery Hard ScobeyVery Hard Seeley LakeModerately Hard ShawmutModerately Hard ShelbyVery Hard ShepherdModerately Hard SheridanVery Hard SidneyVery Hard SilesiaVery Hard Silver GateSlightly Hard Silver StarSlightly Hard SimmsModerately Hard SomersSlightly Hard StanfordHard StevensvilleHard StockettModerately Hard StrykerSlightly Hard SulaModerately Hard Sun RiverModerately Hard SunburstVery Hard SuperiorHard Swan LakeSlightly Hard SweetgrassVery Hard TerryHard Thompson FallsHard Three ForksSlightly Hard TostonSlightly Hard TownsendVery Hard Trout CreekHard TroySoft TurnerVery Hard Twin BridgesVery Hard TwodotSlightly Hard UlmModerately Hard UticaHard ValierVery Hard VaughnModerately Hard VictorModerately Hard VidaVery Hard Virginia CitySlightly Hard VolborgHard WalkervilleSoft WarmspringsVery Hard West GlacierSlightly Hard West YellowstoneSlightly Hard WestbyHard White Sulphur SpModerately Hard WhitefishSlightly Hard WhitehallModerately Hard WhitetailHard WhitewaterHard WhitlashVery Hard WibauxVery Hard WillardHard WilsallSoft WinnettVery Hard WisdomModerately Hard Wise RiverModerately Hard Wolf CreekSlightly Hard Wolf PointVery Hard WordenModerately Hard WyolaModerately Hard YellowtailHard ZortmanVery Hard ZurichVery Hard