Two navigation locks on the Mississippi River reopened during the weekend as receding water allowed for barge navigation, the U.S. Army Corps of Engineers said on Monday.

The Corps closed Lock 24 near Clarksville, Missouri, and Lock 25 near Winfield, Missouri, on April 20 as river levels surged following heavy rains across the U.S. Midwest.

Water levels were still too high to reopen the Kaskaskia Lock and Dam on the Kaskaskia River, the Corps said in a statement.

About 60 percent of U.S. grain exports are transported via the Mississippi River and its tributaries from farm areas in the Midwest to export facilities at the Gulf of Mexico. (Reporting by Mark Weinraub; Editing by Gerald E. McCormick)