River Facts

An earthquake on Dec. 16, 1811 caused parts of the Mississippi River to flow backwards.

During spring tides, a tidal bore called the Pororoca rolls up the Amazon River, creating a continuous wave up to 4 meters high that can be surfed for over 12 kilometers. The phenomenon is strongest between February and March when Atlantic tides push ocean water upstream against the river's flow.

When a speeding GMC truck crashed through a bridge fence and plunged upside down into Utah's Jordan River in 2014, Leo Montoya Jr. was the first person to jump in - then shouted at frozen bystanders until more than a dozen strangers waded in beside him. Together they physically flipped the submerged vehicle upright, held one boy's head above water, and got all three trapped teenagers out alive.