It’s tempting to forget about Lake Champlain when contemplating New England’s maritime history—focusing instead on the clipper ships and schooners that plied the Atlantic. But the lake was once the lifeblood of the country’s interior, before the cutting of the Erie Canal and settlement of Ohio territory moved the frontier further to the West. Champlain’s history dates back even before the Pilgrims landed at Plymouth Rock, when Native Americans traversed its shores in birch-bark canoes, and French trappers established camps on its islands.

The Lake Champlain Maritime Museum, just a few miles form the lakeshore (4472 Basin Harbor Rd., 802/475-2022, www.lcmm.org, 10 a.m.–5 p.m. daily late May–mid-Oct., $10 adults, $9 seniors, $6 students 5–17, children under 5 free, admission good for two consecutive days), does an exceptional job of bringing alive the scope of the lake’s domestic and military history, with a hands-on boat-building workshop, an exhibit on the more than 200 shipwrecks that line the lake-bottom, and an interactive display on the lake’s importance in the Revolutionary War.

Perhaps the biggest surprise is the story of patriot-turned-traitor Benedict Arnold, who led a heroic defense of the lake in the early years of the war. Arnold commissioned a fleet of gunships to be built at the lake’s southern end in Skenesborough, and fought a hopeless battle with the British off the shore of Valcour Island, a few miles up from Basin Harbor. The engagement scuttled British plans for invasion in 1776, leaving another year for the Americans to plan their defenses.

In 1997, the Lake Champlain Maritime Museum undertook the mammoth task of rebuilding one of Arnold’s gunboats, the Philadelphia II, which now floats in the harbor.