Margrethe Lake
Margrethe Lake in Crawford County, Michigan has a water quality grade of A (Excellent). Water clarity: 16 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 1 µg/L. Maximum depth: 65 ft. Surface area: 1919.7 acres.
- Clarity
- 16 ft
- Max depth
- 65 ft
- Area
- 1,920 acres
- Type
- Oligotrophic
- Trend
- → Stable
- Public access
- Yes
Next lake in Crawford County
Swipe left or right on this bar to open the next or previous lake.
Free interactive depth-contour map of Margrethe Lake, reaching a maximum surveyed depth of 65 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Michigan DNR.
Margrethe Lake is a 1,920-acre cold, clear oligotrophic lake in Crawford County, Michigan with a maximum depth of 65 feet. Water quality is graded A based on 2 sampling years through 2023. Water clarity is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 2 other monitored lakes in Crawford County, Margrethe Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, EGLE, last sampled 2023-09-08. Grade methodology: LakeQuality methodology.
Watch Margrethe Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Crystal clear, you can see 16 ft down. Phosphorus level: 8 µg/L. Chlorophyll-a: 1 µg/L. Trophic State Index: 34.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 16 ft | Not graded |
| Phosphorus | 8 µg/L | Good |
| Chlorophyll-a (Algae) | 1 µg/L | Good |
| Trophic State Index (TSI) | 34 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Margrethe Lake
Compare lakeside cabins, hotels, and vacation rentals near Margrethe Lake in Crawford 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 Margrethe Lake
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 trip? Cabins and lodging at Margrethe Lake → · more Michigan lake trips
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 65 ft |
| Surface Area | 1,920 acres |
| Public Access | Yes |
Recreation & Access
- Lake Margrethe (South)Public
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Margrethe Lake
Water Quality Trend: → Stable
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.982 m/yr | 6 |
| Phosphorus | ↓ Declining | +0.35 µg/L/yr | 5 |
| Chlorophyll-a | → Stable | 0 µg/L/yr | 3 |
EPA Impairment Status
Margrethe Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MI040601030104-04 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Margrethe Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Harrietta-Grayling Fish HatchGrayling · 4.5 mi away · NPDES MI0059209Recent 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.
County Ranking
Ranked #1 of 3 lakes in Crawford County
Nearby Lakes in Crawford County
Frequently asked questions about Margrethe Lake
Where is Margrethe Lake?
- Margrethe Lake is a lake in Crawford County, Michigan. LakeQuality grades it A for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Margrethe Lake?
- Margrethe Lake in Crawford County, Michigan has a water quality grade of A (Excellent). Water clarity: 16 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 1 µg/L. Maximum depth: 65 ft. Surface area: 1919.7 acres.
Is Margrethe Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Margrethe Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 1 µg/L. Always check local health department advisories before swimming.
How deep is Margrethe Lake?
- Margrethe Lake has a maximum depth of 65 feet. The lake covers 1919.7 acres.
Are there boat ramps on Margrethe Lake?
- Margrethe Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Margrethe (South). Public access is listed as yes.
Explore Margrethe Lake across LakeQuality
Fish species and top-graded lakes across Michigan
Fish species and best lakes in Crawford County
Species activity outlook by water temperature and season
Where to stay at Michigan's top lakes, each with its grade
Low nutrients, clear water, excellent for swimming
Michigan's cleanest and most-polluted lakes, ranked
More Michigan Lake Rankings
Other Grade A Lakes in Michigan
Kalkaska County · 24 ft
Kalkaska County · 23 ft
Kalkaska County · 18 ft
Roscommon County · 5 ft
Otsego County · 11.3 ft
Gladwin County · 16.5 ft
Oligotrophic Lakes in Michigan
Where this data comes from
84 measurements from 1 monitoring station, 2016–2023. Retrieved from the EPA Water Quality Portal on 2026-08-26.
Collected and reported by
- Michigan EGLE - MiCorps
21MICH_MICORPS84 samples · 2016–2023
Analytical methods
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
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
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Named boat-access points from the USGS National Boat Ramps inventory