How hard is the water in Lincoln County, MT?

3.4 grains per gallon

You do not need a softener here.

The median hardness measured in Lincoln County, MT is 59 mg/L as calcium carbonate, which is 3.4 gpg. That is soft on the USGS scale. It comes from 142 samples at 16 sites between 1990 and 2026, drawn from groundwater wells, which is what most taps and private wells in the county draw on.

How much it varies here

Half the sites came in between 1.4 and 5 gpg. That spread crosses a decision line, so some homes here land on a different answer. A $10 test strip on your own tap settles it. Confidence in the county figure: high (how it is measured).

What to do next

You can skip the softener. At 3.4 gpg the most a softener would fix is the odd water spot. If a salesperson in Lincoln County says otherwise, ask to see their reading in grains per gallon and compare it with this one. Because Lincoln County straddles a decision line, check your own tap with a $10 test strip before you spend anything.

More on when a softener is not worth it.

From 0.8 to 5.9 gpg

The softest single sample on record in Lincoln County was 14 mg/L and the hardest 101 mg/L, a 7-fold gap. The top quarter of sites read above 5 gpg and the bottom quarter below 1.4 gpg.

Wells 3.4 gpg, rivers and lakes 2.5 gpg

142 groundwater samples from 16 wells put the median at 58.8 mg/L. 1,845 surface samples from 200 sites put it at 43 mg/L. In Lincoln County the wells come out 0.9 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. The two sources are close, so the county figure should hold whichever one your tap is on.

Lincoln County against the rest of Montana

Among the 56 Montana counties with data, Lincoln County is the softest. Across the whole country it is harder than 24% of counties.

Hardest: Rosebud County at 138.9 gpg. Closest to Lincoln County: Stillwater County (4.1), Mineral County (4.5), Ravalli County (4.6).