Two canoes crossing open water between forested points in the Boundary Waters

Updated August 2026

Biggest Lake in Idaho: Lake Pend Oreille (92,764 acres)

Lake Pend Oreille is Idaho's largest lake per the Idaho Department of Fish and Game. Below: 50 Idaho lakes ranked by surface area.

The largest lake in Idaho is Lake Pend Oreille at 92,764 acres , in Bonner, Kootenai County, according to the Idaho Department of Fish and Game.

See our Lake Pend Oreille water-quality report card NR

Source: Idaho Department of Fish and Game (2026-07-30 (accessed)). The table below ranks the Idaho lakes in our own index by surface area.

Lakes with area data

92,764

Largest (acres)

1,106

Median of top 50

9/50

Reservoirs (vs natural)

Reading Idaho's size profile

Idaho's largest lake by surface area is Lake Pend Oreille in Bonner County, spanning 92,764 acres. Most of Idaho's biggest waters are natural basins left by glaciers, with stable shorelines and deep main basins.

Surface area is a poor proxy for water quality on its own — a large lake can hold a clean, deep core and a nutrient-loaded bay at the same time. Each lake below links to its full report card with grade, clarity, depth, and EPA impairment status. Area figures come from state DNR surveys and the USACE National Inventory of Dams; grades come from EPA and state monitoring data.

The 50 biggest lakes in Idaho by surface area

#	Lake	County	Surface area	Max depth	Grade
1	Lake Pend Oreille	Bonner	92,764 acres	-	NR
2	Priest Lake	Bonner	23,426 acres	-	NR
3	Blackfoot Reservoir	Caribou	16,913 acres	-	NR
4	Dworshak Reservoir	Clearwater	16,362 acres	-	NR
5	Palisades Lake	Bonneville	16,230 acres	-	C
6	Lake Walcott	Cassia	12,400 acres	-	D
7	Island Park Lake	Fremont	8,680 acres	-	D
8	C J Strike Reservoir	Owyhee	6,208 acres	-	NR
9	Henrys Lake	Fremont	6,190 acres	-	NR
10	Payette Lake	Valley	5,075 acres	-	NR
11	Lake Hayden	Kootenai	3,858 acres	-	NR
12	Deadwood Reservoir	Valley	3,800 acres	-	A
13	Arrowrock Reservoir	Elmore	3,256 acres	-	NR
14	Mud Lake	Jefferson	3,118 acres	-	NR
15	Magic Reservoir	Blaine	3,079 acres	-	NR
16	Crane Creek Reservoir	Washington	2,921 acres	-	NR
17	Salmon Falls Creek Reservoir	Twin Falls	2,887 acres	-	NR
18	Lucky Peak Lake	Ada	2,762 acres	-	NR
19	Ririe Reservoir	Bonneville	1,560 acres	-	NR
20	Spirit Lake	Kootenai	1,549 acres	-	NR
21	Redfish Lake	Custer	1,504 acres	-	NR
22	Little Payette Lake	Valley	1,461 acres	-	NR
23	Upper Priest Lake	Bonner	1,340 acres	-	NR
24	Paddock Valley Reservoir	Washington	1,182 acres	-	NR
25	Mackay Reservoir	Custer	1,178 acres	-	NR
26	Oxbow Reservoir	Adams	1,106 acres	-	NR
27	Black Cnyn Reservoir Ns of	Gem	1,100 acres	-	A
28	Little Camas Reservoir	Elmore	1,048 acres	-	NR
29	Alexander Reservoir	Caribou	1,007 acres	-	NR
30	Ross Lake	Owyhee	1,006 acres	-	NR
31	Palisades Reservoir	Bonneville	979 acres	-	NR
32	Black Canyon Reservoir	Gem	876 acres	-	NR
33	Alturas Lake	Blaine	838 acres	-	NR
34	Murtaugh Lake	Twin Falls	819 acres	-	NR
35	Cocolalla Lake	Bonner	815 acres	-	NR
36	Cave Lake	Kootenai	760 acres	-	NR
37	Mountain View Lake	Owyhee	680 acres	-	D
38	Swan Lake	Kootenai	669 acres	-	NR
39	Hauser Lake	Kootenai	604 acres	-	NR
40	Rays Lake	Jefferson	598 acres	-	NR
41	Littlewood Lake	Blaine	590 acres	-	D
42	Chatcolet Lake	Kootenai	578 acres	-	NR
43	Anderson Lake	Kootenai	503 acres	-	NR
44	Killarney Lake	Kootenai	502 acres	-	NR
45	Harrison Slough	Kootenai	493 acres	-	NR
46	Wilson Lake Reservoir	Jerome	489 acres	-	NR
47	Twin Lakes Reservoir	Franklin	439 acres	-	NR
48	Oneida Narrows Reservoir	Franklin	430 acres	-	NR
49	Warm Lake	Valley	423 acres	-	NR
50	Bybee Reservoir	Owyhee	408 acres	-	NR

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Frequently Asked Questions

What is the largest lake in Idaho?

Lake Pend Oreille, at 92,764 acres, in Bonner, Kootenai County. Source: Idaho Department of Fish and Game, 2026-07-30 (accessed).

How is lake surface area measured?

Surface area comes from state DNR lake surveys and, for reservoirs, US Army Corps of Engineers (USACE) National Inventory of Dams records. Area is reported in acres at normal pool level. Reservoirs rise and fall with management and drought, so their listed area is the long-term normal rather than a single-day reading.

Are Idaho's largest lakes natural or reservoirs?

Of the top 50 Idaho lakes by area, 9 sit on a dammed river (reservoirs) and 41 are natural basins. Glacial states (MN, WI, MI, NY) skew natural; plains and southern states (MO, IA, ND, OH) skew toward reservoirs built for water supply, flood control, and recreation.

Do larger lakes have better water quality?

Not reliably. Quality varies more within a big lake than between lakes — a large lake can have a clean, deep main basin and a murky, algae-prone bay fed by a tributary, so one grade can mask wide swings. Depth, watershed land use, and how fast the lake flushes matter far more than raw surface area.

How big is the typical Idaho lake in this ranking?

Across the top 50 Idaho lakes by surface area, the median is 1,106 acres (Oxbow Reservoir). This list is biased toward the biggest waters; the typical Idaho lake is far smaller.

Where to stay near Idaho's largest lakes

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

Deepest lakes in Idaho →Cleanest lakes in Idaho →Largest lakes (all states) →All Idaho lakes →