Lincoln County Lake Quality

Montana, 26 lakes, average grade A (Excellent)

Lincoln County's 26 graded lakes fall in the moderate-density bracket for {{stateName}}. The county-level average smooths over real differences — a single agricultural watershed near the southwest corner can pull the average down even if the rest of the county runs clean. On average, Lincoln County lakes grade an A. That puts it near the top of the {{stateName}} county ranking.

Most of the county's monitored lakes are shallow — under 50 feet — which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed. Nla Lake (A) is the cleanest in the county.

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Quick Answers for Lincoln County

Cleanest lakes in Lincoln County →Cleanest lakes in Montana →Safest swimming lakes in Montana →

Planning a trip? Check special fishing regulations for Nla Lake — or check the official Montana fishing regulations.

All Lakes in Lincoln County

Rank	Lake	Grade	Clarity	Phosphorus
1	Nla Lake	A	16.9 ft	13.8 µg/L
2	Nla Lake	A	25.4 ft	13.4 µg/L
3	Lake Koocanusa	A	-	4 µg/L
4	Lake Koocanusa	A	-	4.5 µg/L
5	Big Therriault Lake	A	37.3 ft	-
6	Tetrault Lake	A	21.8 ft	-
7	Murphy Lake	A	15 ft	-
8	Sophie Lake	A	21.1 ft	-
9	Glen Lake	A	19.9 ft	-
10	Sophie Lake	A	-	11.1 µg/L
11	Tetrault Lake	A	-	7.5 µg/L
12	Dickey Lake	A	-	11.6 µg/L
13	Fish Lake	A	-	9.5 µg/L
14	Murphy Lake	A	-	6.5 µg/L
15	Glen Lake	A	-	4.5 µg/L
16	Big Therriault Lake	A	-	2.4 µg/L
17	Nla Lake	A	14.1 ft	11.9 µg/L
18	Lake Koocanusa	A	13.1 ft	8 µg/L
19	Lake Koocanusa	A	11.5 ft	6 µg/L
20	Lake Koocanusa	B	14.8 ft	-