A humpback whale tail slaps the waters surface of the Sacramento River on Friday, May 25, 2007, in Rio Vista, Calif. 

This article originally appeared on KCRA.com.The humpback whale captured on video breaching in the Sacramento River near Rio Vista last week is headed west in the Delta toward San Francisco Bay, according to the Marine Mammal Center.

The Marine Mammal Center said the whale, named "Rio," was last spotted on Friday and their westward move was a "very positive sign."

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Denny Glover said he was fishing with two other people south of the Rio Vista Bridge when one member........

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