Lakes With Algae Problems in Montana
10 lakes in Montana report elevated algae levels (chlorophyll-a above 20 µg/L). These lakes are most likely to develop blue-green algae blooms during warm, calm summer weather. Avoid swimming during visible blooms and rinse pets after contact.
Ranked List
| # | Lake | County | Grade | Clarity | Phosphorus | Algae |
|---|---|---|---|---|---|---|
| 1 | Nla Lake | Blaine | F | 0.5 ft | 485.3 µg/L | 367.2 µg/L |
| 2 | Nla Lake | Chouteau | F | 1.1 ft | 343000 µg/L | 192.1 µg/L |
| 3 | Nla Lake | Blaine | F | 1.2 ft | 373.7 µg/L | 171.2 µg/L |
| 4 | Nla Lake | Hill | F | 0.8 ft | 390000 µg/L | 144.4 µg/L |
| 5 | Nla Lake | Valley | F | 1 ft | 336.5 µg/L | 137 µg/L |
| 6 | Nla Lake | Phillips | F | 0.9 ft | 266.5 µg/L | 94.5 µg/L |
| 7 | Nla Lake | Sheridan | F | 0.6 ft | 3436000 µg/L | 43 µg/L |
| 8 | Boneau Reservoir | Chouteau | D | - | 50 µg/L | 39 µg/L |
| 9 | Nla Lake | Liberty | F | - | 738000 µg/L | 31 µg/L |
| 10 | Nla Lake | Toole | F | 2.6 ft | 2170 µg/L | 28.4 µg/L |