The final boats passed through the Upper St. Anthony Falls lock in downtown Minneapolis Tuesday night before the lock closed permanently. The shutdown is part of an effort to stem the upstream migration of invasive carp on the Mississippi River.
It's the first time a navigable waterway in the United States has been closed to slow the spread of an invasive species. The lock had been in operation for nearly 52 years.
Rick Snell and his mother Joan guided their powerboat through the lock just before midnight. Theirs was among the final few vessels to pass through the lock headed downstream.
"We went on a big boat ride for about a week. We went up to Stillwater, Prescott, Hudson and now we decided last minute to catch the last pass through the locks," he said. "It's a sad thing. This upper part of the river is great. So there'll be small boats up here now that will enjoy it by themselves, and canoers and kayakers will own this part of the river and it'll be great for them. "
More than two dozen kayakers paddled through the lock just before it closed.
The Corps will continue to operate the lock for flood control, but the Army is building a bulkhead above the lock to permanently block boat traffic.