Slim Lake under flat overcast, dark open water running to a low wooded shore

Updated August 2026 · Top 50 of 1,668 lakes with a surveyed depth

Deepest Lakes in Minnesota

Lake Saganaga is Minnesota's deepest natural lake at 280 ft, per the Minnesota DNR. Mahnomen Mine Pit and the neighboring Alstead and Arco pits near Crosby reach 525 ft, but the Minnesota DNR lists those flooded iron-ore pits separately from natural lakes. Mapped and ranked below: the 50 deepest of 1,668 Minnesota lakes with a surveyed maximum depth, led by Gilbert Pit Lake at 443 ft.

Map · 50 ranked lakesTap a pin for its lakeTap a pin for the lake's report card

Loading map…

Graded A–FNot rated#1 in this rankingPins are this ranking's lakes at their surveyed locations.

Top 50 Deepest Lakes in Minnesota (by max depth)

#	Lake	County	Max depth	Mean depth	Surface area	Grade
1	Gilbert Pit Lake	St. Louis	443 ft	—	243 ac	NR
2	St James Pit Lake	St. Louis	381 ft	115 ft	124 ac	NR
3	Iron Chief Complex Lake	St. Louis	262 ft	—	207 ac	NR
4	Lasalle Lake	Hubbard	213 ft	81 ft	238 ac	A
5	Watap Lake	Cook	210 ft	—	1,993 ac	NR
6	Sagamore Mine Lake	Crow Wing	210 ft	63 ft	119 ac	NR
7	Gabimichigami Lake	Cook	209 ft	—	1,186 ac	NR
8	Ten Mile Lake	Cass	208 ft	52 ft	5,080 ac	A
9	Loon Lake	Cook	202 ft	—	1,095 ac	A
10	Gunflint Lake	Cook	200 ft	—	4,009 ac	A
11	Strup Lake	Lake	195 ft	—	1,689 ac	NR
12	Sand Point Lake	St. Louis	184 ft	—	8,527 ac	NR
13	Larson Lake	Itasca	177 ft	—	208 ac	B
14	Lac la Croix Lake	St. Louis	168 ft	—	29,597 ac	NR
15	Crooked Lake	Lake	165 ft	37 ft	10,360 ac	NR
16	Carlos Lake	Douglas	163 ft	50 ft	2,605 ac	A
17	Rainy Lake	Koochiching	161 ft	32 ft	210,200 ac	NR
18	Trout Lake	Itasca	157 ft	—	1,743 ac	A
19	Caribou Lake	Itasca	152 ft	—	247 ac	NR
20	Little Saganaga Lake	Cook	150 ft	—	1,627 ac	NR
21	Snowbank Lake	Lake	150 ft	—	4,655 ac	B
22	Steamboat Bay Lake	Cass	150 ft	19 ft	103,444 ac	A
23	Six Lake	Otter Tail	140 ft	—	197 ac	A
24	Elmo Lake	Washington	140 ft	31 ft	257 ac	A
25	South Lake	Cook	140 ft	—	1,145 ac	NR
26	Miner'S Pit West Lake	St. Louis	140 ft	—	141 ac	NR
27	Whitefish Lake	Crow Wing	138 ft	—	7,714 ac	A
28	Rose Lake	Otter Tail	137 ft	—	1,200 ac	NR
29	Long Lake	Hubbard	135 ft	31 ft	1,926 ac	A
30	Big Sand Lake	Hubbard	135 ft	—	1,639 ac	A
31	Kabekona Lake	Hubbard	133 ft	53 ft	2,433 ac	A
32	Koronis Lake	Stearns	132 ft	29 ft	2,968 ac	C
33	Duncan Lake	Cook	130 ft	47 ft	477 ac	NR
34	Kekekabic Lake	Lake	130 ft	—	55 ac	NR
35	Oyster Lake	St. Louis	130 ft	—	763 ac	NR
36	Mountain Lake	Unknown	130 ft	42 ft	1,344 ac	NR
37	Rove Lake	Cook	130 ft	42 ft	1,344 ac	NR
38	Roosevelt Lake	Cass	129 ft	—	1,511 ac	A
39	Long Lake	Otter Tail	128 ft	—	1,289 ac	A
40	Big Trout Lake	Crow Wing	128 ft	52 ft	1,366 ac	A
41	Burntside Lake	St. Louis	126 ft	—	7,314 ac	A
42	Round Lake	Aitkin	125 ft	—	737 ac	A
43	Jasper Lake	Cook	125 ft	31 ft	246 ac	NR
44	Mina Lake	Douglas	123 ft	28 ft	411 ac	NR
45	Big Watab Lake	Stearns	123 ft	44 ft	246 ac	NR
46	Deer Lake	Itasca	121 ft	42 ft	4,093 ac	A
47	Bluewater Lake	Itasca	120 ft	—	364 ac	A
48	Otter Tail Lake	Otter Tail	120 ft	—	14,079 ac	A
49	White Earth Lake	Becker	120 ft	—	1,989 ac	A
50	Peter Lake	Cook	120 ft	—	282 ac	NR

Sources and method

Max and mean depth: Minnesota DNR LakeFinder lake surveys. Surveyed depths only; modeled estimates are never ranked. A dash means the survey did not record a mean.
Deepest natural lake: Lake Saganaga, 280 ft, per the Minnesota DNR, 2013 (MN DNR page "Reviewed 2013"; retrieved 2026-07-30). Lake Saganaga report card (its record carries no surveyed depth, so it is not in the table)
Grade: A–F water-quality grade from EPA Water Quality Portal nutrient and algae sampling, where enough recent samples exist to support one; the dashed NR mark otherwise. Depth is not part of the grade.
Map pins: the 50 table rows with surveyed coordinates, colored by grade. No other lakes are plotted.

Get updates on Minnesota's deepest lakes

New grades and algae readings on these waters as samples come in. Unsubscribe anytime.

Frequently Asked Questions

What is the deepest lake in Minnesota?

Lake Saganaga, at 280 ft, in Cook County, is the deepest natural lake. Mahnomen Mine Pit and the neighboring Alstead and Arco pits near Crosby reach 525 ft, but the Minnesota DNR lists those flooded iron-ore pits separately from natural lakes. In the surveyed-depth table, Gilbert Pit Lake ranks first at 443 ft. Source: Minnesota DNR, 2013 (MN DNR page "Reviewed 2013"; retrieved 2026-07-30).

Why does Gilbert Pit Lake rank first in the table?

Gilbert Pit Lake has the greatest surveyed maximum depth in the table, 443 ft. The Minnesota DNR names Lake Saganaga (280 ft) as the deepest natural lake. Mahnomen Mine Pit and the neighboring Alstead and Arco pits near Crosby reach 525 ft, but the Minnesota DNR lists those flooded iron-ore pits separately from natural lakes.

How are lake depths measured?

Maximum depth is the deepest point at full-pool water level, from state agency bathymetric surveys and, for reservoirs, dam-design records. The ranking uses surveyed depths only, never modeled estimates. Everyday water level can sit below the surveyed figure during drawdowns or drought. Mean depth, the average across the whole basin, is listed where a survey recorded it.

Why are some Minnesota lakes so much deeper than others?

Lake depth depends on how the lake formed. Glacial lakes (common in MN, WI, MI, NY) were carved by ice sheets and can exceed 200 ft. Reservoir lakes (common in IA, MO, OK, KS) are shaped by river valley depth at the dam site — typically 50-150 ft at the dam, much shallower upstream. Flooded mine pits can be deeper still. Oxbow lakes and pothole lakes formed by river meandering or glacial pitting tend to be shallower, usually under 30 ft.

Does deeper mean cleaner?

Not directly, but deeper lakes tend to be cleaner on average. Depth creates thermal stratification in summer, isolating cold deep water from surface algal blooms. Deep lakes also resist nutrient resuspension from wind-driven sediment mixing. That said, many deep lakes still suffer from impairment if the watershed loads heavy phosphorus — each lake's page carries its grade and EPA impairment status.

What's the average depth of Minnesota lakes in this ranking?

Across the 50 deepest Minnesota lakes, the average maximum depth is 163 ft and the median is 140 ft (Miner'S Pit West Lake). This is the top of 1,668 lakes with a surveyed depth, so it is biased toward deep lakes; the typical Minnesota lake is shallower.

Where to stay near Minnesota's deepest lakes

Planning a trip? Jump to live cabin, resort, and hotel availability near Minnesota's deepest lakes.

Largest lakes in Minnesota →Cleanest lakes in Minnesota →All Minnesota lakes →Minnesota state record fish →