Lewis and Clark County, MT

ZIP 59601

In ZIP 59601, 6 of the 12 things we check have at least one part graded D or F.

• Drinking water: Mobile City Home Park No 2 meets every EPA legal limit; 8 contaminants are above health goals, led by pfos at 3.2× California’s Public Health Goal.
• Nearest Superfund site: East Helena Site, 0.6 miles away.
• Largest share of modeled toxic air from industry: American Chemet Corp (88%), mostly copper compounds.
• Fine particles (PM2.5) average 6.3 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 26,812 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 59601

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

Based on 11 census tracts · compiled September 10, 2026 · how each grade works and its sources

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