SACRAMENTO, Calif. - A mother and baby whale may have found their bearings in the Sacramento River.

The Coast Guard says the two humpbacks, which traveled some 90 miles up the Sacramento this past week, are heading back toward the Pacific Ocean.

A Coast Guard spokesman says the whales have gone only about five miles so far, but are in the deep channel moving along well. Nine vessels are following to make sure they don't turn back.

There are some obstacles ahead, including muddy deltas, pylons of four bridges, and the Golden Gate Bridge.

It's unclear what caused the whales to suddenly start traveling in the right direction. Both are injured, apparently from a ship's propeller.