State distribution
Hardness across indexed ZIPs
Counts describe published ZIP profiles, not a population-weighted statewide sample.
Soft · 0–60 PPM35
Moderately hard · 61–120 PPM29
Hard · 121–180 PPM17
Very hard · 181+ PPM48
State water index
Montana water hardness
Search 133 indexed communities and 145 ZIP profiles, then compare the underlying utility, source, distance, and reporting context.
Median indexed hardness
122PPM
Hard
Indexed range 0.2–799.5 PPM
- ZIP profiles
- 145
- Cities
- 133
- Matched utilities
- 342
- Counties
- 50
Understanding Montana
Why local comparisons matter here
Montana combines Rocky Mountain headwaters and valleys with broad eastern plains, shallow alluvial sources, and deeper sedimentary aquifers.
In this index, very hard is the largest category, covering 48 of 129 profiles with hardness data. The state median is 122 PPM, but the full indexed range is 0.2–799.5 PPM.
Evidence coverage
What the current records support
- Hardness estimate
- 89%
- Lead 90th percentile
- 100%
- Copper 90th percentile
- 39%
85
Low-confidence hardness profiles
85
Nearest site more than 25 miles away
Reported source water
Utility source mix
- Groundwater
- 278
- Surface water
- 63
- Groundwater influenced by surface water
- 1
Highest medians
Hardest indexed cities
- 1. Malta800 PPM
- 2. Forsyth624 PPM
- 3. Hysham620 PPM
- 4. Plentywood581 PPM
- 5. Sidney488 PPM
Lowest medians
Softest indexed cities
- 1. Lewistown0 PPM
- 2. Fort Benton0 PPM
- 3. Ulm22 PPM
- 4. Sun River22 PPM
- 5. West Yellowstone29 PPM
City directory
Explore Montana by city
Search by city or county, then sort by name, hardness, or ZIP coverage.
133 cities · 145 ZIP profiles
133 cities found
Page 1 of 6
Absarokee
Stillwater County · 1 ZIP
96PPM
Single indexed valueNo active flag
Antelope
Sheridan County · 1 ZIP
360PPM
Single indexed valueNo active flag
Ashland
Powder River County · 1 ZIP
197PPM
Single indexed valueNo active flag
Augusta
Lewis And Clark County · 1 ZIP
43PPM
Single indexed valueNo active flag
Babb
Glacier County · 1 ZIP
74PPM
Single indexed valueNo active flag
Bainville
Roosevelt County · 1 ZIP
328PPM
Single indexed valueNo active flag
Baker
Fallon County · 1 ZIP
199PPM
Single indexed valueNo active flag
Ballantine
Yellowstone County · 1 ZIP
302PPM
Single indexed value1 active record
Basin
Jefferson County · 1 ZIP
38PPM
Single indexed valueNo active flag
Belfry
Carbon County · 1 ZIP
207PPM
Single indexed valueNo active flag
Big Sandy
Chouteau County · 1 ZIP
—
No hardness estimateNo active flag
Big Sky
Madison County · 2 ZIPs
38PPM
Range 8–68.9No active flag
Big Timber
Sweet Grass County · 1 ZIP
96PPM
Single indexed valueNo active flag
Bigfork
Lake County · 1 ZIP
35PPM
Single indexed valueNo active flag
Billings
Yellowstone County · 3 ZIPs
235PPM
Range 228–235No active flag
Black Eagle
Cascade County · 1 ZIP
164PPM
Single indexed valueNo active flag
Bozeman
Gallatin County · 1 ZIP
87PPM
Single indexed value1 active record
Brady
Pondera County · 1 ZIP
—
No hardness estimateNo active flag
Bridger
Carbon County · 1 ZIP
214PPM
Single indexed valueNo active flag
Broadus
Powder River County · 1 ZIP
215PPM
Single indexed valueNo active flag
Bynum
Teton County · 1 ZIP
150PPM
Single indexed valueNo active flag
Carter
Chouteau County · 1 ZIP
80PPM
Single indexed valueNo active flag
Chinook
Blaine County · 1 ZIP
—
No hardness estimateNo active flag
Circle
Mccone County · 1 ZIP
308PPM
Single indexed valueNo active flag
County comparison
Highest indexed county medians
| County | Median | Range | ZIP profiles |
|---|---|---|---|
| Treasure County | 620 PPM | 620–620 | 1 |
| Phillips County | 537 PPM | 274–799.5 | 3 |
| Rosebud County | 521 PPM | 417.5–623.5 | 3 |
| Richland County | 467 PPM | 445.5–488 | 2 |
| Garfield County | 446 PPM | 446–446 | 1 |
| Wibaux County | 415 PPM | 415–415 | 1 |
| Carter County | 400 PPM | 400–400 | 1 |
| Sheridan County | 360 PPM | 301–580.5 | 5 |
| Roosevelt County | 321 PPM | 297–328 | 3 |
| Dawson County | 318 PPM | 318–318 | 1 |
| Mccone County | 307 PPM | 306.5–308 | 2 |
| Daniels County | 307 PPM | 306.5–308 | 2 |