Millsite Lake is a cold, clear oligotrophic lake in Jefferson County, New York. Water quality is graded A based on 1 sampling years through 2020. The lake supports 2 documented fish species including Landlocked Salmon and Rainbow Trout. Public access is available with 5 public boat landings. Compared to the 1 other monitored lakes in Jefferson County, Millsite Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, New York DNR, last sampled 2020-09-19. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Crystal clear, you can see 27.9 ft down. Trophic State Index: 29.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 27.9 ft | A |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 29 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Millsite Lake
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Fish Species
Click a species to see every graded lake where it is documented.
Fishing Millsite Lake
Recreation & Access
Location
County Ranking
Ranked #1 of 2 lakes in Jefferson County
Nearby Lakes in Jefferson County
Explore Millsite Lake across LakeGrade
Fish species and top-graded lakes across New York
Fish species and best lakes in Jefferson County
Species activity outlook by water temperature and season
Where to stay at New York's top lakes, each with its grade
Low nutrients, clear water, excellent for swimming
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More records, surveys & data sources
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth is a modeled estimate.
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Millsite Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Redwood SdTheresa · 1.3 mi away · NPDES NY0215911Recent violation
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Data Sources
Water quality data from the EPA Water Quality Portal
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Grading methodology based on Metropolitan Council standards
Public boat-access points from the USGS National Boat Ramps inventory
Most recent sample: 2020-09-19
Monitoring stations: 1