Humphrey the whale is one of the most famous humpbacks in history, thanks to two journeys he took into San Francisco Bay. Humphrey first entered the bay in 1985, swimming up the Sacramento River and into Rio Vista, Calif. Rescuers led him back to sea using a "sound net," in which people aboard boats loudly banged on steel pipes, driving him in the opposite direction.
A granite memorial was erected in Rio Vista in 1986, but the Bay Area still hadn't seen the last of Humphrey. He showed up again in 1990, and was again rescued. Humphrey has since been spotted only once, near the Farallon Islands in 1991, but he may have inspired two other wayward humpbacks: The mother-daughter duo Delta and Dawn also swam up the Sacramento River in 2007.