Lone Mountain Guest Ranch
PWSID: MT0001820
This system has no unresolved violations. The most recent violation on record was 2024-12-30.
This system has more violations on record than 98% of water systems in Montana.
Violation trend: 1.0 per year over the last 5 years, down from 32.4 per year in the previous 5.
System Details
| Population Served | 75 |
| Service Connections | 25 |
| Water Source | Groundwater |
| System Type | Non-Transient Non-Community |
| Owner | Private |
| Status | Active |
| City | Big Sky |
| EPA ZIP on File | 59716 |
Areas Served
- Big Sky, Gallatin County
Lead & Copper Testing
| Contaminant | Level | EPA Action Level | Status |
|---|---|---|---|
| Lead (90th percentile) | 0.0076 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0014 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0008 mg/L | 0.015 mg/L | Below Action Level |
Violation History (170 total)
| Contaminant | Violation | Date | Health-Based | Status |
|---|---|---|---|---|
| 5000 | MR | 2024-12-30 | Returned to Compliance | |
| 0700 | MR | 2022-12-01 | Returned to Compliance | |
| 0700 | MR | 2022-12-01 | Returned to Compliance | |
| 0700 | MR | 2022-12-01 | Returned to Compliance | |
| 0700 | MR | 2022-12-01 | Returned to Compliance | |
| 1010 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1010 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1010 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1015 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1015 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1015 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1020 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1020 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1020 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1025 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1025 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1025 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1035 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1035 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1035 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1036 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1036 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1036 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1074 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1074 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1074 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1075 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1075 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1075 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1085 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1085 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1085 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1045 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1045 | MR | 2020-01-01 | Major | Returned to Compliance |
| 1045 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2005 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2005 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2005 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2010 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2010 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2010 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2015 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2015 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2015 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2020 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2020 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2020 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2031 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2031 | MR | 2020-01-01 | Major | Returned to Compliance |
| 2031 | MR | 2020-01-01 | Major | Returned to Compliance |
Showing 50 of 170 historical violations.
Understanding This Water System's Record
Lone Mountain Guest Ranch is a non-transient non-community water system that draws from groundwater sources and serves a population of 75 in Big Sky, Montana. This page shows its complete compliance history as reported to the EPA's Safe Drinking Water Information System (SDWIS), the federal database that tracks every public water system in the United States.
What Do These Violations Mean?
Health-based violations mean the system exceeded an EPA maximum contaminant level (MCL) or failed to provide required treatment. These indicate potential health risks from contaminants like lead, arsenic, bacteria, nitrates, or disinfection byproducts. Non-health-based violations involve monitoring, reporting, or procedural requirements — the system missed a testing deadline or failed to notify customers, but contaminant levels were not necessarily unsafe.
What Should You Do?
Your water utility is required to publish an annual Consumer Confidence Report (CCR) that details test results and any violations. If your system has active health-based violations, consider a certified water filter rated for the specific contaminants involved. The contaminant guides on this site explain health risks and filter options for common pollutants. For the most current results, contact your water utility directly — EPA data can lag weeks or months behind real-time testing.