1
AClear Lake
Itasca County, Minnesota · mi from Dark Lake
- +Two grade letters higher (D → A)
- ++8.5 ft water clarity
- +Lower phosphorus (9 vs 139.5 µg/L)
Cleaner Lakes Than Dark Lake
5 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Dark Lake carries a Grade D (Poor) water quality score. Within 30 miles, 5 lakes hold a higher grade. Clear Lake (Itasca County, Grade A, null mi away) is the closest meaningful upgrade.
Reviewed by LakeQuality Editorial Team · Updated
2
ATrestle Lake
Itasca County, Minnesota · mi from Dark Lake
- +Two grade letters higher (D → A)
- ++8.4 ft water clarity
- +Lower phosphorus (13 vs 139.5 µg/L)
3
BMoose Lake
Itasca County, Minnesota · mi from Dark Lake
- +Two grade letters higher (D → B)
- ++1.6 ft water clarity
- +Lower phosphorus (22 vs 139.5 µg/L)
4
BDora Lake
Itasca County, Minnesota · mi from Dark Lake
- +Two grade letters higher (D → B)
- ++1.1 ft water clarity
- +Lower phosphorus (25 vs 139.5 µg/L)
5
CIsland Lake
Itasca County, Minnesota · mi from Dark Lake
- +Higher grade (D → C)
- ++2.5 ft water clarity
- +Lower phosphorus (32.5 vs 139.5 µg/L)
Reading the cohort
5 cleaner lakes sit within 30 miles of Dark Lake in the EPA water-quality dataset. With that many higher-grade neighbors close by, Dark Lake's Grade D reflects something specific to the lake itself — not a regional water-quality ceiling. The neighbor list below isn't a small set of marginal upgrades; it's a real cohort of meaningfully cleaner choices for the same Minnesota weekend.
The closest cleaner alternative — Clear Lake in Itasca County, Grade A — sits miles from Dark Lake. At that distance, the substitution cost is essentially zero: same drive time, same regional access, demonstrably cleaner water on the EPA indicators. For repeat visitors who care about clarity or phosphorus levels, swapping the routine to Clear Lake is mostly a habit change rather than a logistics change.
The EPA water-quality grading combines clarity (Secchi depth), phosphorus, and chlorophyll-a measurements from state environmental sampling. A higher letter grade reflects measurably cleaner water on those indicators, not subjective beauty or access quality — a Grade A lake might have worse boat-launch facilities or shoreline access than a Grade C neighbor, so the ranking is one input alongside the rest of trip planning. See the methodology page for the full grading formula.
How this list is built
Every lake on LakeQuality has a calculated grade from EPA Water Quality Portal samples — secchi depth, total phosphorus, and chlorophyll-a measured against Metropolitan Council thresholds. To suggest cleaner alternatives, we filter lakes within 30 miles to those with a strictly higher numeric score, then rank by grade improvement with a small proximity tiebreak. Cross-state and limited-data lakes are excluded so the list stays locally relevant.