Giant Floating Island Periodically Blocks
Giant Floating Island Periodically Blocks: Wisconsin’s Lake Chippewa is home to a massive floating island that periodically blocks a vital bridge, requiring coordinated efforts from local boaters to dislodge it.
Lake Chippewa, also known as Chippewa Flowage, was formed in 1923 by flooding a large swamp. Soon after, many peat bogs began rising to the surface, becoming fertile spots for plant seeds carried by wind and birds. Over time, vegetation ranging from grasses to trees took root, their expanding roots causing the floating bogs to enlarge. Today they vary from parking space-sized to spanning several acres. The largest, dubbed the “Forty Acre Bog” on the west side, hosts mature trees. Nearly every year, dozens of boaters team up to push it away from a bridge connecting the lake’s east and west sides.
“It happens almost annually. It takes a community effort with the winds behind you to push them in,” a local told Northern News Now.
According to the Chippewa Flowage website, the unique floating islands originate as mudflats rising from the underwater swamp. Eventually, vegetation starts growing. The oldest islands have trees that act as sails when the wind blows, moving the entire mass around the lake.
“It’s one of the first things you check in the morning – where’s the bog?” said resident Denny Reyes.
The decades-old floating island doesn’t always drift, but when it does, it can obstruct the vital bridge – the only passage between the east and west sides. The only way to dislodge it is with boats – dozens working in unison with the wind behind them. Last year, 25 boats pushed the island from the bridge.
“When we move it, we have to get it in the right spot or it can drift back in days,” said local Greg Kopke.
As floating islands like the Forty Acre Bog provide habitat, they are legally protected and cannot be dismantled.