Iron Lake vs Lac la Croix Lake
Water quality, depth, fish species, and recreation comparison.
Iron Lake has a higher water quality grade (D, Poor) than Lac la Croix Lake (F, Very Poor). Both are in St. Louis County, Minnesota.
Iron Lake and Lac la Croix Lake are both in Minnesota — a same-state head-to-head where the comparison comes down to lake-specific differences in depth, watershed, and monitoring history rather than the broader state-level water-quality regime. These two are within a letter of each other on the rubric — Iron Lake (D) versus Lac la Croix Lake (F). The deciding factors for a recreational visitor are likely physical (depth, access, fish species) rather than water-quality differences.
With grades this close, the choice between the two lakes turns on non-water-quality factors: depth, fish species, public access, distance from home. The per-lake pages below cover all of those.
Iron Lake
Murky, only visible to about 5 ft.
Lac la Croix Lake
Very murky, less than 2.5 ft of visibility.
Side-by-Side Metrics
| Metric | Iron Lake | Lac la Croix Lake |
|---|---|---|
| Overall Grade | D (Poor) | F (Very Poor) |
| Water Clarity | 5 ft | 2.5 ft |
| Phosphorus | No data | No data |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | 64 ft | 30 ft |
| Surface Area | 2.0K acres | 1.0K acres |
| Public Access | No | No |
| Fish Species | 9 | 10 |
| Trophic State | eutrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Iron Lake wins on overall water quality with a Grade D versus Lac la Croix Lake's Grade F. Water clarity: 5 ft vs 2.5 ft. For more fish-species variety, Lac la Croix Lake edges ahead with 10 documented species.