Flathead County, MT

ZIP 59901

In ZIP 59901, 9 of the 12 things we check have at least one part graded D or F.

• Drinking water: Pheasant Haven Estates meets every EPA legal limit; 4 contaminants are above health goals, led by lead at 50× California’s Public Health Goal.
• Nearest Superfund site: Anaconda Aluminum Co Columbia Falls Reduction Plant, 3.6 miles away.
• Largest share of modeled toxic air from industry: Weyerhaeuser Nr (100%), mostly formaldehyde.
• Fine particles (PM2.5) average 7.3 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 45,820 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 59901

• Superfund sites nearbyA to F
• Factories and industrial sitesA to D
• Oil and gas wellsA to B
• Parks and nature nearbyB to F
• Air qualityA to C
• Drinking water qualityC to F
• Pesticide useD to F
• Neighborhood health statusB to D
• Past wildfire impactsA to D
• Past flood impactsA
• Noise levelsA to D
• Radiation signalsC to F

Based on 22 census tracts · compiled September 10, 2026 · how each grade works and its sources

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