Boating Lake County Blog

Grass Lake: the Third Largest Lake in the Chain


A hundred years ago, Grass Lake wasn’t really a lake at all. It was a huge marsh whose expansive lotus beds, with their intensely colored blossoms, were the region’s top tourist attraction from the late 19th through early 20th centuries. It wasn’t until a dam was built in 1907, that the water levels rose high enough to transform the wetlands into a shallow lake.

At 1,360 acres, Grass Lake is the third largest of the nine major lakes, which are linked by channels to form the famed Chain O’Lakes—the most popular inland recreational waterway per acre in the United States, according to the Fox Waterway Agency. With an average depth of three feet and six feet at its deepest, Grass Lake is also the shallowest in the Chain. 

By 1960, Grass Lake’s signature lotus blossoms were nearly gone, done in by increasing boat traffic and rising and falling water levels. It wasn’t until a no wake zone,” extending 150 feet from the shoreline, was imposed in 1993, that the lotus beds began re-establishing themselves along the shore. 

The shallow depth and broad no-wake zone has made Grass Lake a favorite of fishermen. Channel catfish and carp are bountiful. Largemouth bass, bluegill, pumpkinseed, yellow bass, muskie, walleye, perch, white bass, northern pike, and smallmouth bass can also be found here.

Grass Lake borders the popular 2,800-acre Chain O’Lakes State Park which offers free boat ramps, as well as biking and hiking trails, horse riding trails and lakeside camping. Keep in mind that all boats operating on the Chain—including kayaks and canoes—must have a Fox Waterway Agency sticker, in addition to their state registration. 

One vestige of the Grass Lake’s marshy past is still going strong. Originally part of a resort built on a peninsula jutting out into Grass Lake—before the water levels rose and isolated it—the site is now known as Blarney Island.” And it’s one of the most unique entertainment venues in the world, because it’s in the middle of Grass Lake. The only way to reach the palm-tree festooned, five-acre Key West of the Midwest” is by boat or boat shuttle leaving from the shoreline’s Port Of Blarney in Antioch.

Another historic carryover is Thunder on the Chain, the weekly powerboat races where speeds can reach a mind-blowing 150 mph. Now held every Thursday evening during the summer at Blarney Island, the races have drawn crowds to Grass Lake since the competitions began in 1905. The last race is held on Labor Day, September 2. Don’t miss out! 

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