Mesotrophic Lakes in Oregon

19 mesotrophic lakes in Oregon. Moderate nutrients, good water quality.

Mesotrophic lakes are the productive middle of the trophic scale — TSI between 40 and 50. Clear enough to be inviting, productive enough to support a strong fishery, with moderate phosphorus and a modest algal community that does not dominate the optical signal. 19 lakes in {{stateName}} sit in the mesotrophic band. About 0% are deep (50+ ft); the rest are shallower basins where watershed management keeps nutrients from pushing the system into eutrophy.

Mesotrophic lakes tend to grade B or C on the LakeGrade rubric — the productive-but-clear band lines up with the middle of the letter grades.

#	Lake	County	Grade	Clarity	Depth	TSI
1	Pine Hollow Reservoir	Wasco	A	-	-	45
2	Lost Creek Lake	Jackson	A	-	-	41
3	Emigrant Lake	Jackson	A	-	-	42
4	Foster Lake	Linn	A	-	-	40
5	Lava Lake	Deschutes	A	17.6 ft	-	43
6	Wickiup Reservoir	Deschutes	A	11.2 ft	-	41
7	Billy Chinook Reservoir	Jefferson	B	8.4 ft	-	43
8	Crane Prairie Reservoir	Deschutes	B	8.4 ft	-	45
9	Crane Prairie Reservoir	Deschutes	B	12.5 ft	-	44
10	Detroit Lake	Marion	B	-	-	47
11	Crane Prairie Reservoir	Deschutes	B	-	-	48
12	Lake Billy Chinook Metolius Arm	Jefferson	B	-	-	46
13	Siltcoos Lake	Lane	B	-	-	49
14	Lemolo Lake	Douglas	B	-	-	49
15	Billy Chinook Reservoir	Jefferson	B	4.4 ft	-	46
16	Phillips Lake	Baker	B	5.9 ft	-	48
17	Wickiup Reservoir	Deschutes	B	8.2 ft	-	48
18	Willow Creek Reservoir	Morrow	C	9.8 ft	-	44
19	Lava Lake	Deschutes	C	6.6 ft	-	48

All mesotrophic lakes →Minnesota version →Wisconsin version →Illinois version →Michigan version →Iowa version →Ohio version →Pennsylvania version →New York version →Missouri version →Indiana version →North Dakota version →South Dakota version →Florida version →Colorado version →North Carolina version →Vermont version →Texas version →Arkansas version →Oklahoma version →Kansas version →Nebraska version →Nevada version →Arizona version →Idaho version →Montana version →New Mexico version →All Oregon lakes →

Source: EPA National Aquatic Resource Surveys, 2026.