Portage Lake
Portage Lake in Cass County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 1528 acres.
- Area
- 1,528 acres
- Public access
- Yes
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Why Portage Lake has no grade
We grade a lake only when the monitoring record supports a letter: 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 Portage Lake, no water-quality sampling on record for this lake.
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.
Portage Lake is a 1,528-acre lake in Cass County, Minnesota. Limited fish-species data available. Public access is available with 2 public boat landings.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled recent years. Grade methodology: LakeQuality methodology.
Watch Portage Lake water quality
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Swimming Safety
Not ratedElevated nutrients
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Portage Lake
These readings exist but are not enough for an A–F grade — see why.
No clarity data. Trophic State Index: undefined.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) |
Where to stay near Portage Lake
Compare lakeside cabins, hotels, and vacation rentals near Portage 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 Portage Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 1,528 acres |
| Public Access | Yes |
No bathymetric survey has been published for Portage Lake, so its depth is not documented here.
Recreation & Access
- Portage LakePublic
- Iowana Beach ResortSemi-private
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Portage Lake
Nearby Lakes in Cass County
Frequently asked questions about Portage Lake
Where is Portage Lake?
- Portage Lake is a lake in Cass County, Minnesota. LakeQuality has not rated this lake (UNRATED) — no water-quality sampling on record for this lake.
What is the water quality grade for Portage Lake?
- Portage Lake in Cass County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 1528 acres.
Is Portage Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Portage Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
Are there boat ramps on Portage Lake?
- Portage Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Portage Lake, Iowana Beach Resort. Public access is listed as yes.
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Where this data comes from
Measurements for Portage Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.
Other records on this page
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory