Delta And Dawn Home Free?

Sandra Hughes is a CBS News correspondent based in Los Angeles.

It has been 18 days since the mother humpback and her calf were discovered heading up the Sacramento River the wrong way. Under the terms of the Endangered Species Act, state officials are given the power and the finances to pay for rescue efforts when an animal on the list is in trouble. The mother and calf were. They were stuck in the Port of Sacramento 90 miles upstream in fresh water! They had wounds and the mother, they believed, might still be nursing her calf. Without salt water the mother couldn't feed. It could turn into a serious situation. They believed these two had wandered off their migration course from Mexico. Usually Humpbacks give birth in the warm waters between Hawaii and Mexico during the winter and then head up to Alaska for feeding time over the summer with their young in tow.

So rescue workers from California Fish and Game decided to try and lure the whales back down stream and into the open ocean. First they started with those weird underwater whale noises. These were whale feeding noises. When that didn't work they realized maybe they were using the wrong kind of whale feeding sounds.

Attempt number two to get them down the river was herding. They used a flotilla of boats to try and ease them down stream. This sort of worked but then the whales dove back under the flotilla.

So, when the flotilla didn't work, the rescuers added pipe banging to the flotilla idea to scare the whales to the sea. All of this served to move them a little. But inevitably the whales would stop and swim in circles. Scientists more than once said "the whales will do what the whales want to do."

Then on Sunday, Delta and Dawn inexplicably took off and swam down river and toward the San Francisco Bay. By Monday things were looking good for their safe return to the ocean. Tuesday they were in the bay speeding toward the Golden Gate Bridge and their freedom.

After a shot of antibiotics the mother's wound on her back was healing. They tried to put a tracking device on the mother to follow them out to the open sea.

By nightfall Tuesday, the two had slowed and were circling off Tiburon, a coastal town just three miles away from the Golden Gate Bridge.

Wednesday morning, we took a fishing boat out into the San Francisco Bay, and like the rescue boats, we couldn't see anything -- just fog and a calm bay. The two humpbacks now known as Delta and Dawn (named by California's Lt. Governor for the California Delta and the "dawn" of a new day) had vanished -- it appeared this time, for good. Rescuers said if they didn't surface by the afternoon, they were pretty sure they had slipped out during the night.

The tracking device had failed and no one may ever really know why or when the two made their way back to open sea waters. But most everyone is glad that they did!! All along the route back toward the ocean, Delta and Dawn had a fan club following them. Not since Humphrey, a lost male humpback did this 22 years ago, did anyone see such a sight. It took a month to lure Humphrey back to the ocean. Delta made it in just 18 days and she was a lot farther inland.

Having been married 12 years, this does not surprise me. I can imagine the underwater scene now:

Delta: "Anyone down here know how to get to the Golden Gate Bridge????"

Humphrey: "I know exactly where I'm going. I looked at the map before I left home."