Humphrey stayed a considerable time in 1990 in the embayment immediately north of Sierra Point in Brisbane, California where occupants of the Dakin Building could observe his antics. Humphrey became beached on a mudflat in San Francisco Bay to the north of Sierra Point and to the south of Candlestick Park. He was extricated from the mudflat with a large cargo net and support from the Marine Mammal Center and a U.S. Coast Guard boat.