Mistake Island, Lake Champlain: Depths, Location, and the Story Behind the Name

Tucked into Lake Champlain's northwestern corner, Mistake Island sits 6 miles northeast of Plattsburgh, New York — a 47-acre wooded outpost in the lake's widest reach. The surrounding water plunges to 180 feet (55 m) at its deepest, making this area a favored habitat for lake trout, landlocked salmon, and the lake's legendary (if unverified) resident, Champ.

Geographic Context

• Lake: Lake Champlain — 120 miles long, 12 miles max width, 400 ft max depth
• Region: "The Inland Sea" — broad section between Grand Isle, VT and Plattsburgh, NY
• Coordinates: 44°44′N, 73°20′W
• Ownership: Private (seasonal camps); publicly accessible waters

Why "Mistake"?

Local lore offers two theories:

1. Survey error: Early 19th-century surveyors allegedly misplaced the island on charts, labeling it "Mistake" — the name stuck.
2. Navigation hazard: Low-profile island in foggy conditions caused groundings; "Mistake" warned captains.

Neither is documented; the name appears on 1850s charts.

Recreation and Ecology

• Fishing: Lake trout, landlocked salmon, bass, pike, perch
• Diving: Clear water, shipwrecks nearby (General Butler, O.J. Walker)
• Birding: Common terns, ospreys, bald eagles nest nearby
• Paddling: Sea kayaking destination; part of Lake Champlain Paddlers' Trail

Environmental Note

Lake Champlain faces phosphorus pollution (algal blooms), invasive species (zebra mussels, spiny water flea), and climate-driven warming. Mistake Island's deep, cool waters may become critical thermal refuge for cold-water fish.

A small island with a big name, deep water, and a front-row seat on Lake Champlain's past — and future.