ST. LOUIS (AP) Drought-drained rivers are offering a rare and fleeting glimpse into years gone by. Lack of rain has left many rivers at low levels unseen for decades, creating problems for river commerce and recreation and raising concerns about water supplies and hydropower if the drought persists.

But receding water offers an occasional treasure trove of history. An old steamboat is now visible on the Missouri River near St. Charles and other old boats are showing up elsewhere. A World War II minesweeper, once moored as a museum at St. Louis before it was torn away by Mississippi River floodwaters in 1993, has become visible, rusted but intact.

And a rock containing what is believed to be an ancient map has emerged in the Mississippi River in southeast Missouri.

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