Discover the Deepest Lake in Idaho

Written by Cindy Rasmussen
Updated: June 1, 2023
© Kirk Fisher/
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Much of Idaho is covered in lush green forests. In fact, 40% of the state is national forest. These forests provide natural recreational opportunities, as well as habitat for a variety of animals. Interspersed throughout the forests are wide open bodies of water, like lakes, rivers, and clear streams that are amazing places for boating, swimming, and fishing. The fifth deepest lake in the U.S. is in Idaho. You may or may not know that there is also a top-secret Naval Base in Idaho. Read on to find out all about the deepest lake in Idaho!

What Is the Deepest Lake in Idaho?

Lake Pend Oreille, Idaho
Lake Pend Oreille is the deepest lake in Idaho and one of the deepest in the United States.

©Jeffrey T. Kreulen/

The deepest lake in Idaho is Lake Pend Oreille. In fact, it is the fifth deepest lake in the U.S. Lake Pend Oreille is located in the northern panhandle of Idaho tucked between the Idaho Panhandle National Forest to the south and the Kaniksu National Forest to the north. The lake gets its name from the French words “Oreille” which means ear and “Pend” which means hanging or pendant. It refers to the Kalispel Native Americans that lived in the area who wore ear pendants. 

How Deep Is the Deepest Lake in Idaho?

The deepest lake in Idaho is 1,158 feet deep. For reference, if you dropped the Eiffel Tower into Pend Oreille Lake you wouldn’t be able to see the top of it.

Where Is Pend Oreille Lake Located on a Map?

Pend Oreille Lake is primarily in Bonner County, with its southern tip in Kootenai County, which is the site of Farragut State Park.

At the northern tip of the lake is the city of Sandpoint, set between the Selkirk and Cabinet mountains and located 80 miles northeast of Spokane, Washington, and 50 miles away from Canada. Sandpoint is around seven hours’ drive east of Seattle.

Is There a Top-Secret Naval Base on Pend Oreille Lake?

Though it is not top secret, the U.S. Naval Acoustic Research Detachment (ARD) does have a base on the southern end of the lake. It operates out of Bayview, ID just north of Farragut State Park. The conditions on Pend Oreille are ideal for testing the acoustics of submarines. The deep, deep waters mimic some of the deeper ocean conditions while also providing a safe, controlled testing environment. They study propulsion design (how fast and how quickly it can maneuver), sonar development, and a variety of acoustic designs.

Are There Any Sunken Submarines in Pend Oreille Lake?

There aren’t any sunken submarines in this lake, but there is an old navy barge and an unarmed torpedo! The problem is, due to the great depth of the lake, recovering these items is not cost effective. The Naval barge was even carrying $1 million worth of equipment, but it was too expensive to recover. Additionally, wo boxcars careened off the tracks near Trestle Creek in the 1930’s and plummeted into the lake. They are still down there.

Is There a Sea Monster in Pend Oreille Lake?

Sea monster
Some believe a sea monster, such as the Monasaurus pictured above, lives in Pend Oreille Lake.

©Daniel Eskridge/

When bystanders see the Pend Oreille Paddler (the alleged giant sea monster that lives in the lake) they call in experts to do a “drive by” (or float by) to check out the reports. Frequently, people are mistaking an enormous moss-covered downed tree for this mythical sea monster. But many legends keep the locals entertained. Most likely, residents have been seeing a lake sturgeon, which looks a bit like a monster. Lake Sturgeons can get to be 6 ½ feet long and weigh more than 100 pounds!

What Real Sea Monsters (the Biggest Trophy Fish) Have Been Caught in Pend Oreille?

Bull Trout
The biggest bull trout in Idaho was caught in Pend Oreille Lake.

©Streamside Adventures/

Anglers have pulled three state record-breaking fish from Pend Oreille Lake. The first is an old record dating way back to 1949. The biggest Bull Trout (Dolly Varden) ever caught in Idaho was caught in Pend Oreille. Due to the fact that it is now illegal to harvest this species, the record will stand for good. Nelson Higgins caught this record-breaker that weighed in at 32 pounds! An even older record dates back to 1947 when Wes Hamlet caught a Gerrard Rainbow Trout that weighed 37 pounds! The third record is more recent. On August 6, 2010, Dale Hofmann landed an impressive 6 ½ pound Lake Whitefish.

What Unique Species of Fish Inhabits Pend Oreille Lake?

The giant Kamloops rainbow trout, one of the rare native fish, lives in Pend Oreille Lake. They are thought to originate from British Columbia’s Lake Kootenay, which is near the city of Kamloops. These massive trout can reach 20-30 pounds and thrive in the cool deep waters of Pend Oreille.

How Does the Deepest Lake in Idaho Compare to the Deepest Lake in the U.S.?

Crater Lake National Park
Crater Lake, in Oregon’s Crater National Park, the deepest lake in the U.S.


The deepest lake in Idaho, Pend Oreille Lake, is 1,158 feet deep. If you compare that to the deepest lake in the U.S, you will see it is not quite as deep. Crater Lake in Oregon is 1,943 feet deep, making it the deepest lake in the U.S. While Pend Oreille is nestled in the forest, Crater Lake is at the top of a collapsed volcano. There are no Kamloops trout in the lake but there are rainbow trout and Kokanee salmon. Because the lake was formed entirely from rain and snow, there are no native fish in this lake. But between the years 1888 and 1941, Fish and Wildlife experts attempted to establish seven different fish species. The Kokanee salmon and rainbow trout were the only two species to maintain a healthy population.

What Are the 5 Deepest Lakes in the U.S.?

The five deepest lakes in the United States are:

  1. Crater Lake, Oregon: 1,943 feet
  2. Lake Tahoe, California/Nevada: 1,645 feet
  3. Lake Chelan, Washington: 1,486 feet
  4. Lake Superior, Minnesota/Wisconsin/Michigan: 1,332 feet
  5. Pend Oreille Lake, Idaho: 1,158 feet.

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The Featured Image

Lake Pend Oreille
Lake Pend Oreille is a beautiful lake in Idaho.
© Kirk Fisher/

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About the Author

I'm a Wildlife Conservation Author and Journalist, raising awareness about conservation by teaching others about the amazing animals we share the planet with. I graduated from the University of Minnesota-Morris with a degree in Elementary Education and I am a former teacher. When I am not writing I love going to my kids' soccer games, watching movies, taking on DIY projects and running with our giant Labradoodle "Tango".

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