Lake Pend Oreille
Bottle Bay Rd
Sandpoint, ID
Idaho's deepest lake plunges more than a thousand feet to a cold, silent bottom, so silent that the Navy tests its submarines here, a thousand miles from any ocean.
Lake Pend Oreille is the largest lake in Idaho and one of the deepest in the country, dropping more than a thousand feet to a flat, cold, muddy bottom. It fills a glacier-carved trench in the Panhandle, forty-some miles long, ringed by three mountain ranges, with the lively resort town of Sandpoint on its north shore. On the surface it is a stunning mountain lake. Underneath, it hides one of the strangest secrets in the state.
That depth, and the near-perfect silence of the deep water, is why the United States Navy runs a submarine research station here, a thousand miles from the nearest ocean. Below a hundred feet the lake stays near freezing all year, the mountains block outside noise, and the southern basin has almost no currents. It adds up to some of the quietest large-scale testing water on Earth, and the Navy has used it to make its submarines silent since World War II.
What Guests Love
- The sheer scale and depth of Idaho's largest lake, ringed by mountains
- The unlikely story of a Navy submarine-testing station in landlocked Idaho
- Trophy fishing for kamloops rainbow trout, kokanee, and bull trout
- Sandpoint's beaches, long bridge, and easy access to swimming and boating
Worth Knowing
- The Navy's Acoustic Research Detachment at Bayview is an active, restricted facility; you can see it from the water but not tour it
- The lake is huge and can build serious waves in wind; boaters should watch the weather
- Below a hundred feet the water stays near freezing year-round, so this is not a warm swimming lake except in the shallows in summer
- Winters are cold and gray; summer and early fall are the seasons for the water
Details
Sandpoint, ID
Learn about Lake Pend Oreille
The Navy's inland lake
At Bayview, on the lake's south end, the Navy operates the Acoustic Research Detachment, described as the only large-scale model submarine acoustic testing facility in the world. Here engineers run scale models of submarines through the deep, still water to measure and reduce the sounds a boat makes, the science of staying undetected.
The lake earned this role in World War II, when the government built the Farragut Naval Training Station on its south shore. At its peak in 1942 the base held some 55,000 people, briefly the largest community in Idaho, and over its short life it trained close to 300,000 sailors, making it one of the largest naval training centers in the world. The base closed in 1946, but the Navy kept a toehold that grew into today's acoustic research station.
A glacier-carved deep
Lake Pend Oreille sits in a trough gouged by the great ice sheets of the last Ice Age, which ground down through the mountains and left a basin far deeper than the surrounding valleys. The same Ice Age floods that shaped much of the inland Northwest passed through this country, and the lake is one of their legacies.
That glacial origin explains the lake's extraordinary depth and its cold, clear water. The steep, forested slopes of the Selkirk and Cabinet mountains plunge straight into the lake, giving it the fjord-like feel that makes the shoreline drives and boat trips so memorable.
Fish and wildlife
The lake is famous among anglers for its huge Gerrard-strain rainbow trout, known locally as kamloops, along with kokanee salmon and native bull trout. The fishery has ridden a rollercoaster over the decades, crashing after the 1960s and rebounding through careful management, and it remains a serious trophy destination.
Around and above the water, the Panhandle wilds are alive: bald eagles and ospreys hunt the lake, deer and elk move through the forest, and the surrounding mountains hold moose, bear, and even the rare woodland caribou and grizzly in the high Selkirks. Waterfowl gather in the bays, and the shoreline forest holds a rich birdlife.
Seasons on the lake
Summer is the season for Lake Pend Oreille: swimming off Sandpoint's beaches, boating and sailing the big open water, and fishing the deep. Early fall brings quiet, golden days and the start of the kokanee run.
Winter is cold and often clouded, though the lake rarely freezes across its deep center, and the nearby mountains draw skiers to Schweitzer above Sandpoint. For time on the water, aim for the warm months, and always respect how quickly wind can turn a lake this size rough.
Closest Boutels
The closest Boutel™ stays, so you can turn this stop into an overnight. Each is an independently owned, editorially selected place to stay.
Things to Do Near Sandpoint
Sandpoint
North shore
A beloved resort town on the lake, with beaches, the long Sandpoint bridge, a walkable downtown, and Schweitzer ski resort above it.
Farragut State Park
South end
A large state park on the grounds of the WWII naval training station, with a museum, trails, and lake access at Bayview.
Schweitzer Mountain
About 11 miles from Sandpoint
Idaho's largest ski resort, with big views over Lake Pend Oreille and summer lift-served hiking and biking.