Mary Lake
Dickinson County, Michigan230 acresView mapDirections
EGLE publishes the water-quality measurements for Mary Lake. Here is what has been measured.
- 80 ft max depth
- Limited data
Mary Lake in Dickinson County, Michigan has water-quality measurements published by EGLE, shown here as reported. Water clarity: 14.5 ft visibility. Maximum depth: 80 ft. Surface area: 230 acres.
Free interactive depth-contour map of Mary Lake, reaching a maximum surveyed depth of 80 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Michigan DNR.
Mary Lake is a 230-acre lake in Dickinson County, Michigan with a maximum depth of 80 feet. Overall water quality is declining over recent sampling years. The lake supports 1 documented fish species including Lake herring.
Source: EPA Water Quality Portal sampling records, EGLE, last sampled 2022-09-05. Methodology: how these readings are compared.
What Mary Lake is good for
From access and monitoring records, not editorial picks.
- Clear water14.5 ft of visibility
- Deep water80 ft surveyed max depth
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Mary Lake is safe to swim in today is a call for the Michigan Department of Environment, Great Lakes, and Energy (EGLE) and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Mary Lake
These are the measurements EGLE publishes for Mary Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 14.5 ft. TSI 39.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 14.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 39 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Mary Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
80 ft
Surface area
230 acres
Stays via Stay22
Stays near Mary Lake
Compare lakeside cabins, hotels, and vacation rentals near Mary Lake in Dickinson County, Michigan — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Mary Lake
Prices for Oct 23–25, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Michigan’s top lakes →
Follow Mary Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fish Species
Click a species to see every lake where it is documented.
Fishing Mary Lake
Water Quality Trend: Worsening
Based on 6 years of monitoring (2016–2022).
Water clarity
Stable6 years
Phosphorus
Worsening+0.96 µg/L/yr4 years
Reservoir Info (USACE NID)
Mary Lake is a man-made reservoir impounded by the Mary Lake Dam, built primarily for other on the Hamilton Creek; concrete-type dam, 7 ft tall and 237 ft long.
- Surface area
- 230 ac
- Normal storage
- 350 ac-ft
- Max storage
- 764 ac-ft
- Drainage area
- 15.1 sq mi
- Hazard class
- Low
- Owner
- Waucedah Township
Source: USACE National Inventory of Dams, NID ID MI01247 · Operator website
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Mary Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Norway WwtpNorway · 4.5 mi away · NPDES MI0020214Recent 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.
Nearby Lakes in Dickinson County
Frequently asked questions about Mary Lake
Where is Mary Lake?
- Mary Lake is a lake in Dickinson County, Michigan. Its water-quality measurements are published by EGLE and shown on this page as reported.
What is the water quality of Mary Lake?
- Mary Lake in Dickinson County, Michigan has water-quality measurements published by EGLE, shown here as reported. Water clarity: 14.5 ft visibility. Maximum depth: 80 ft. Surface area: 230 acres.
Is Mary Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Mary Lake?
- Mary Lake has a maximum depth of 80 feet. The lake covers 230 acres.
What fish are in Mary Lake?
- Fish species found in Mary Lake include Lake herring. Mary Lake is located in Dickinson County, Michigan.
Explore Mary Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
7.3 mi away
Fish species and the cleanest lakes across Michigan
Fish species and best lakes in Dickinson County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Upper Peninsula area
Where to stay at Michigan's top lakes, each with its readings
Michigan's cleanest lakes, ranked on agency measurements
More lakes in Michigan
Other Lakes in Michigan
Oligotrophic Lakes in Michigan
Where this data comes from
64 measurements from 1 monitoring station, 2016–2022. Retrieved from the EPA Water Quality Portal on 2026-08-26.
Collected and reported by
- North American Lake Management Society
NALMS64 samples · 2016–2022
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Regulated discharger data from EPA ECHO (ICIS-NPDES)