Lewis and Clark County, MT

ZIP 59601

In ZIP 59601, 5 of the 12 things we check have at least one part graded D or F.

• Drinking water: Golden Estates Trailer Court has 1 contaminant at or over an EPA legal limit; 7 contaminants are above health goals, led by arsenic at 2,837× 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 (92%), 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 sitesA to C
• Oil and gas wellsA
• Parks and nature nearbyA to C
• Air qualityA
• Drinking water qualityA to D
• Pesticide useC 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 October 25, 2026 · how each grade works and its sources

Loading the full report, with every source…