Lake Mary
Iron County, Michigan263 acresView mapDirections
Not Rated: one monitoring station are on record, but they measured water clarity only. LakeQuality’s A–F method grades total phosphorus, total nitrogen, chlorophyll-a, and turbidity; clarity is shown, not scored.
- 48 ft max depth
- Public access
- Limited data
Lake Mary in Iron County, Michigan is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 19 ft visibility. Maximum depth: 48 ft. Surface area: 262.8 acres.
- Clarity
- 19 ft
- Max depth
- 48 ft
- Area
- 263 acres
- Trend
- → Stable
- Public access
- Yes
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Watch Lake Mary’s letter
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Free interactive depth-contour map of Lake Mary, reaching a maximum surveyed depth of 48 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Michigan DNR.
Why Lake Mary has no grade
Lake Mary has monitoring on record from one station, but only water clarity was measured. LakeQuality’s A–F letter uses total phosphorus, total nitrogen, chlorophyll-a, and turbidity against EPA National Lakes Assessment condition classes. With none of those grading measurements on record, Lake Mary is Not Rated — not an F. Its 19-foot median from 95 readings collected 2016–2022 is still shown as clarity, but clarity alone cannot earn a letter.
Not Rated is EPA Integrated Reporting Category 3 — insufficient information. Everything below that has been measured is still reported on this page.
Sampling is run by EGLE and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Lake Mary is a 263-acre lake in Iron County, Michigan with a maximum depth of 48 feet. Water clarity is improving over recent sampling years. The lake supports 1 documented fish species including Walleye. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, EGLE, last sampled 2022-09-14. Grade methodology: LakeQuality methodology.
What Lake Mary is good for
From access and monitoring records, not editorial picks.
- Clear water19 ft of visibility
- Boat launch1 documented ramp
- Deep water48 ft surveyed max depth
Swimming Safety
Not ratedLimited data
The letter is not a swimming clearance. Check local advisories before you swim.
Water quality measurements for Lake Mary
These readings exist but are not enough for an A–F grade — see why.
Crystal clear, you can see 19 ft down. TSI 35.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 19 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 35 | Oligotrophic |
Low nutrients, clear water. The letter is not a swimming clearance.
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 48 ft |
| Surface Area | 263 acres |
| Public Access | Yes |
Recreation & Access
- Lake MaryPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Lake Mary
Water Quality Trend: → Stable
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.259 m/yr | 7 |
| Phosphorus | ↓ Declining | +0.24 µg/L/yr | 7 |
| Chlorophyll-a | → Stable | -0.06 µg/L/yr | 7 |
Graded lakes near Lake Mary
Lake Mary has no grade, but these lakes within a short drive do.
Nearby Lakes in Iron County
Frequently asked questions about Lake Mary
Where is Lake Mary?
- Lake Mary is a lake in Iron County, Michigan. LakeQuality has not rated this lake (UNRATED) — the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity.
What is the water quality grade for Lake Mary?
- Lake Mary in Iron County, Michigan is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 19 ft visibility. Maximum depth: 48 ft. Surface area: 262.8 acres.
Is Lake Mary safe to swim in?
- The letter is not a swimming clearance. Check local advisories before you swim.
How deep is Lake Mary?
- Lake Mary has a maximum depth of 48 feet. The lake covers 262.8 acres.
What fish are in Lake Mary?
- Fish species found in Lake Mary include Walleye. Lake Mary is located in Iron County, Michigan.
Are there boat ramps on Lake Mary?
- Lake Mary has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Mary. Public access is listed as yes.
Explore Lake Mary across LakeQuality
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Where this data comes from
95 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
NALMS95 samples · 2016–2022
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Named boat-access points from the USGS National Boat Ramps inventory