What is the biggest lake in Washington?

Lake Roosevelt, at 80,000 acres.

Biggest lakes in Washington: the top 10 by size

How big are the biggest lakes in Washington? Here are the top 10, with their size and what to do on each.

The list

Sizes are the published surface area where one exists; the others are our own measure of the water's outline and read "about". Reservoirs shrink and grow with their level, so a dry year shows less water.

#	Lake	Size	Shoreline
1	Lake Roosevelt	80,000 acres	about 292 mi
2	Lake Chelan	33,300 acres	about 109 mi
3	Banks Lake	26,900 acres	about 135 mi
4	Lake Washington	21,600 acres	about 67 mi
5	Potholes Reservoir	about 15,000 acres	about 60 mi
6	Riffe Lake	11,800 acres	about 36 mi
7	Ross Lake	about 8,640 acres	about 45 mi
8	Ozette Lake	7,790 acres	about 27 mi
9	Moses Lake	6,800 acres	about 51 mi
10	Osoyoos Lake	5,730 acres	about 28 mi

1. Lake Roosevelt

Lake Roosevelt covers some 80,000 acres. It lies about 36 miles southeast of Spokane. The usual Washington mix applies: largemouth bass, walleye, crappie and bluegill. On the 3-D map the bed has three point drop-offs and an upper arm: good places to start. Lake Roosevelt, impounded by Grand Coulee Dam, is the largest reservoir in Washington by surface area.

Lake Roosevelt today: water temperature, bite times and the 3-D lake bed

2. Lake Chelan

At 33,300 acres of water, Lake Chelan is a big lake. Expect lake trout, kokanee salmon, trout and smallmouth bass. It goes down to about 1486 ft. Its bed shows three point drop-offs and a steep ledge worth a first look.

Lake Chelan today: water temperature, bite times and the 3-D lake bed

3. Banks Lake

Banks Lake spreads over 26,900 acres of water. It holds walleye, smallmouth bass, largemouth bass and yellow perch. The deepest water is around 177 ft. Its bed shows three point drop-offs and a wind-blown bank worth a first look.

Banks Lake today: water temperature, bite times and the 3-D lake bed

4. Lake Washington

Lake Washington covers some 21,600 acres. The lake is next to Yarrow Point. Trout, largemouth bass, smallmouth bass and yellow perch are the draw. At about 214 ft deep, it stays cooler below the surface well into summer. Its bed shows three point drop-offs and two sheltered coves worth a first look.

Lake Washington today: water temperature, bite times and the 3-D lake bed

5. Potholes Reservoir

Potholes Reservoir covers about 15,000 acres. You will find it about 47 miles south of Richland. O'Sullivan Dam holds it on the Crab Creek. Expect largemouth bass, smallmouth bass, trout and walleye. The deepest water is around 142 ft. On the 3-D map the bed has two point drop-offs and an upper arm: good places to start.

Potholes Reservoir today: water temperature, bite times and the 3-D lake bed

6. Riffe Lake

At 11,800 acres, Riffe Lake is a big lake. You will find it near Morton. Mossyrock Dam holds it on the Cowlitz River. Expect trout, smallmouth bass, largemouth bass and bluegill. The deepest water is around 360 ft. The lake bed gives you three point drop-offs and two sheltered coves to work.

Riffe Lake today: water temperature, bite times and the 3-D lake bed

7. Ross Lake

Ross Lake covers about 8,640 acres. You will find it about 65 miles west of Bellingham. Ross Dam holds it on the Skagit River. The fish here are trout. The deepest water is around 540 ft. On the 3-D map the bed has three point drop-offs and a sheltered cove: good places to start. Ross Lake has no anadromous fish runs because Ross Dam blocks salmon migration up the Skagit River.

Ross Lake today: water temperature, bite times and the 3-D lake bed

8. Ozette Lake

At some 7,790 acres, Ozette Lake is a good-sized lake. You will find it near Forks. The usual Washington mix applies: largemouth bass, crappie, bluegill and catfish. It goes down to about 331 ft. Its bed shows three point drop-offs and two sheltered coves worth a first look. Lake Ozette's deepest point lies more than 300 feet below sea level.

Ozette Lake today: water temperature, bite times and the 3-D lake bed

9. Moses Lake

Moses Lake covers some 6,800 acres. It lies next to Moses Lake. Expect crappie, largemouth bass, smallmouth bass and walleye. It goes down to about 38 ft. Its bed shows three point drop-offs and two sheltered coves worth a first look.

Moses Lake today: water temperature, bite times and the 3-D lake bed

10. Osoyoos Lake

Osoyoos Lake spreads over 5,730 acres. The lake is right by Oroville. Like most lakes its size in Washington, it should hold largemouth bass, crappie, bluegill and catfish. Its bed shows three point drop-offs and a sheltered cove worth a first look.

Osoyoos Lake today: water temperature, bite times and the 3-D lake bed

Big water, big days

Large lakes make their own weather: a breeze that is nothing on a pond builds real waves over miles of open water. Check the wind on the lake page before you launch and keep to the lee shore when it picks up.