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LakeQuality
Late afternoon sun over Slim Lake, scattering a bright path across wind-textured water

Cleanest Lakes in Boulder County, Colorado

Lake Isabelle in Boulder County leads the rankings on measured clarity and nutrients. Below are the top 35 cleanest monitored lakes in Boulder County, Colorado, ranked on EPA nutrient and algae measurements.

Ranked List

#LakeCountyClarityPhosphorusAlgae
1Lake IsabelleBoulder---
2Long LakeBoulder---
3Albion LakeBoulder---
4Goose LakeBoulder---
5Island LakeBoulder---
6Boulder ReservoirBoulder---
7Left Hand Valley ReservoirBoulder---
8Sixmile ReservoirBoulder---
9Hayden LakeBoulder---
10Leggett and Hillcrest ReservoirBoulder---
11Harper LakeBoulder---
12Base Line ReservoirBoulder---
13Marshall LakeBoulder---
14Waneka ReservoirBoulder---
15Barker ReservoirBoulder---
16Gross ReservoirBoulder---
17Gold LakeBoulder---
18Silver LakeBoulder---
19Left Hand ReservoirBoulder---
20Beaver ReservoirBoulder---
21Button Rock ReservoirBoulder---
22Allens LakeBoulder---
23Foothills ReservoirBoulder---
24Clover Basin ReservoirBoulder---
25McIntosh LakeBoulder---
26Lagerman ReservoirBoulder---
27Dodd ReservoirBoulder---
28Gaynor LakeBoulder---
29Terry LakeBoulder---
30Crystal LakeBoulder---
31Walker ReservoirBoulder---
32Divide ReservoirBoulder---
33Ish ReservoirBoulder---
34Burch LakeBoulder---
35McCall LakeBoulder---

More Answers for Boulder County, Colorado

All lakes in Boulder County →Cleanest lakes in Colorado →

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