Trillium Lake
Trillium Lake in Cass County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11.2 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 3.1 µg/L. Maximum depth: 48 ft. Surface area: 155.46 acres.
- Clarity
- 11.2 ft
- Max depth
- 48 ft
- Area
- 155 acres
- Trend
- ↑ Improving
- Public access
- No
- Ice-out
- Apr 16
Next lake in Cass County
Why Trillium Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Trillium Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity, phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Trillium Lake is a 155-acre lake in Cass County, Minnesota with a maximum depth of 48 feet. Overall water quality is improving over recent sampling years. The lake supports 8 documented fish species including black crappie, bluegill, and brown bullhead. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2020-07-05. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Trillium Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Good clarity, visible to about 11.2 ft. Phosphorus level: 17 µg/L. Chlorophyll-a: 3.1 µg/L. Trophic State Index: 43.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11.2 ft | Not graded |
| Phosphorus | 17 µg/L | Not graded |
| Chlorophyll-a (Algae) | 3.1 µg/L | Not graded |
| Trophic State Index (TSI) | 43 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Trillium Lake
Compare lakeside cabins, hotels, and vacation rentals near Trillium Lake in Cass 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 Trillium Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 48 ft |
| Surface Area | 155 acres |
| Shoreline Length | 4.6 mi |
| Littoral Zone | 59% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Trillium Lake
DNR Fisheries Survey Summary
5 surveys on file from MN DNR Fisheries. Most recent: 2002-06-24 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 38.33 | 0.1 lb |
| Yellow Bass | 21.60 | 0.21 lb |
| Yellow Perch | 8.34 | 0.13 lb |
| Pumpkinseed | 5.84 | 0.1 lb |
| Northern Pike | 4.60 | 2.38 lb |
| Black Crappie | 1.94 | 0.21 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.
Bluegill
Yellow Bass
Yellow Perch
Pumpkinseed
From the 2002-06-24 survey
Trillium Lake, also known as Lizzard Lake, is a 136-acre lake located near Hackensack, MN with no public access. With a maximum depth of 48 feet, approximately 67% of the lake is less than 15 feet deep. The Minnesota Department of Natural Resources (MNDNR) has classified Minnesota's lakes into 43 different classes…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Trillium Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — TrilliumFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.579 m/yr | 4 |
| Phosphorus | ↑ Improving | -1.93 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -0.29 µg/L/yr | 4 |
Ice Season
Historical ice data from Minnesota DNR (4 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2004-04-05 (2004) | 2008-04-30 (2008) |
Most recent ice-out: 2008-04-30
EPA Impairment Status
Trillium 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 MN11-0270-00 · Official waterbody report
Graded lakes near Trillium Lake
Trillium Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Cass County
Frequently asked questions about Trillium Lake
What is the water quality grade for Trillium Lake?
- Trillium Lake in Cass County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11.2 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 3.1 µg/L. Maximum depth: 48 ft. Surface area: 155.46 acres.
Is Trillium Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Trillium Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Algae concentration (chlorophyll-a) is 3.1 µg/L. Always check local health department advisories before swimming.
How deep is Trillium Lake?
- Trillium Lake has a maximum depth of 48 feet. The lake covers 155.46 acres.
What fish are in Trillium Lake?
- Fish species found in Trillium Lake include black crappie, bluegill, brown bullhead, largemouth bass, northern pike, pumpkinseed, yellow bullhead, yellow perch. Trillium Lake is located in Cass County, Minnesota.
When does Trillium Lake thaw?
- Trillium Lake typically has ice-out around Apr 16.
Explore Trillium Lake across LakeGrade
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Where this data comes from
3 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA3 samples · 2020
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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
Ice data from Minnesota DNR Climate