Wildlife authorities believe that the mammals had taken the wrong
turn during their annual migration from Baja
"The really worrisome thing is down the Delta," said Brian Gorman, a spokesman for the National Oceanic and Atmospheric Administration. "There are all sorts of diversions and all sorts of wrong turns."
In order to keep the whales on track officials set up other vessels to block entrances to other tributaries on the Sacramento Delta.
"We don't know why they came up the river, or why they are moving down," said Bernadette Fees, a spokeswoman for the California Department of Fish and Game. "As you can see, they are making their own decisions, and we are just trying to keep up with them."