CAPE GIRARDEAU, Mo. — Tim Cox was supposed to be steering an 800-foot string of barges through the twists and turns of the Mississippi River last week, moving tons of grain and coal toward the Gulf of Mexico.

Instead, his towboat and about half a dozen others spent nearly 15 hours stationary in the drought-parched river, about 115 miles south of St. Louis.

The boats had to stop while crews dredged downstream in a desperate attempt to keep the shipping channel open as the river approaches historically low levels.

Cox, second in command on the towboat LJ Sullivan, sat in the captain's chair high above his barges, looking out the wheelhouse windows in disbelief at sandbars and stone dikes that are usually deep underwater.

"I've never seen it this low myself," said Cox, who's worked on Mississippi River towboats for nearly 14 years. "It's a lot more stressful right now."