Ml-Garrison Lake
Ml-Garrison Lake in Aitkin County, Minnesota has a water quality grade of C (Fair). Water clarity: 6.2 ft visibility. Phosphorus: 26 µg/L. Chlorophyll-a (algae): 4.7 µg/L. Maximum depth: 42 ft. Surface area: 128250.02 acres.
- Clarity
- 6.2 ft
- Max depth
- 42 ft
- Area
- 128,250 acres
- Type
- Mesotrophic
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- Apr 25
- Open water
- 222 days
Next lake in Aitkin County
Ml-Garrison Lake is a 128,250-acre mesotrophic lake in Aitkin County, Minnesota with a maximum depth of 42 feet (29-foot average). Water quality is graded C based on 3 sampling years through 2024. Overall water quality is improving over recent sampling years. The lake supports 21 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 2 public boat landings. Compared to the 17 other monitored lakes in Aitkin County, Ml-Garrison Lake ranks #15 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-08. Grade methodology: LakeGrade methodology.
Watch Ml-Garrison Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Grade onlyModerate
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Murky, only visible to about 6.2 ft. Phosphorus level: 26 µg/L. Chlorophyll-a: 4.7 µg/L. Trophic State Index: 49.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.2 ft | Not graded |
| Phosphorus | 26 µg/L | Fair |
| Chlorophyll-a (Algae) | 4.7 µg/L | Good |
| Trophic State Index (TSI) | 49 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Ml-Garrison Lake
Compare lakeside cabins, hotels, and vacation rentals near Ml-Garrison Lake in Aitkin County, Minnesota — 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 Ml-Garrison 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 whole trip? See where to stay at Minnesota’s top lakes →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 42 ft |
| Average Depth | 28.5 ft |
| Surface Area | 128,250 acres |
| Shoreline Length | 105.5 mi |
| Littoral Zone | 26% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Pike Point, GarrisonPublic
- North Garrison BayPublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Ml-Garrison Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Fisheries Survey Summary
36 surveys on file from MN DNR Fisheries. Most recent: 2024-09-01 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Yellow Perch | 219.50 | 0.23 lb |
| Spottail Shiner | 73.62 | 0.02 lb |
| Walleye | 69.99 | 1.23 lb |
| Tullibee (Cisco) | 17.45 | 0.62 lb |
| Smallmouth Bass | 16.43 | 1.74 lb |
| Bluntnose Minnow | 13.53 | 0.01 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Yellow Perch
Spottail Shiner
Walleye
Tullibee (Cisco)
From the 2024-09-01 survey
Sampling Programs Mille Lacs Lake is one of ten lakes in Minnesota's Large Lake Program. These lakes have annual sampling of the fish populations, and frequent creel surveys. Specific to Mille Lacs Lake, sampling programs focusing on Walleye, Yellow Perch, Smallmouth Bass, and Northern Pike are conducted annually.…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Ml-Garrison Lake. 5 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Mille LacsFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Mille Lacs (0134)Aquatic Plant Report · MN DNR LakeFinder
- —Aquatic Plant Report — Mille Lacs (0337)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — Mille LacsFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Mille LacsPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Phosphorus | → Stable | +0.26 µg/L/yr | 5 |
| Chlorophyll-a | ↑ Improving | -1.36 µg/L/yr | 5 |
Ice Season
Historical ice data from Minnesota DNR (123 observations).
Estimated open water season: 222 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2024-03-16 (2024) | 2013-05-16 (2013) |
| Ice-In | 1996-11-19 (1996) | 2001-12-22 (2001) |
Most recent ice-out: 2025-04-18
EPA Impairment Status
Ml-Garrison Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN01-0204-00 · Official waterbody report · Matched by proximity (2.9 km)
County Ranking
Ranked #15 of 18 lakes in Aitkin County
Nearby Lakes With Higher Grades
Ml-Garrison Lake holds Grade C. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Aitkin County
Frequently asked questions about Ml-Garrison Lake
What is the water quality grade for Ml-Garrison Lake?
- Ml-Garrison Lake in Aitkin County, Minnesota has a water quality grade of C (Fair). Water clarity: 6.2 ft visibility. Phosphorus: 26 µg/L. Chlorophyll-a (algae): 4.7 µg/L. Maximum depth: 42 ft. Surface area: 128250.02 acres.
Is Ml-Garrison Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Ml-Garrison Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 4.7 µg/L. Always check local health department advisories before swimming.
How deep is Ml-Garrison Lake?
- Ml-Garrison Lake has a maximum depth of 42 feet and an average depth of 28.5 feet. The lake covers 128250.02 acres.
What fish are in Ml-Garrison Lake?
- Fish species found in Ml-Garrison Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, burbot, common carp, green sunfish, hybrid sunfish, largemouth bass, muskellunge, northern pike, pumpkinseed, rock bass, shorthead redhorse, smallmouth bass, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Ml-Garrison Lake is located in Aitkin County, Minnesota.
When does Ml-Garrison Lake thaw?
- Ml-Garrison Lake typically has ice-out around Apr 25. Ice typically forms around Dec 3. The open water season is approximately 222 days.
Are there boat ramps on Ml-Garrison Lake?
- Ml-Garrison Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Pike Point, Garrison, North Garrison Bay. Public access is listed as yes.
Explore Ml-Garrison Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
Fish species and top-graded lakes across Minnesota
Fish species and best lakes in Aitkin County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Brainerd Lakes area
Top lakes and where to stay in the Mille Lacs Area area
Where to stay at Minnesota's top lakes, each with its grade
Lakes in the Rum River Watershed, ranked by water quality
Lakes in the Pine River Watersheds (Brainerd Lakes), ranked by water quality
Moderate nutrients, good water quality
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Ml-Garrison Lake
Other Grade C Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Compare Ml-Garrison Lake With Nearby Lakes
Where this data comes from
48 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Mille Lacs Band of Ojibwe DNR/Environment
MLBO_DNR_WQX48 samples · 2020–2024
Analytical methods
- 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
- 10200 H ~ Chlorophyll a-b-c Determination
- SM 4500-PJ and NO3-F
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate