Mud Bay is the southernmost reach of Puget Sound, at Eld Inlet just outside the city limits of Olympia, Washington. The name Eld Inlet was officially bestowed after a member of the U.S. Navy's Wilkes Expedition, but "Mud Bay" is a local, informal adoption. It was once a highly productive ground for the Olympia Oyster. The first Indian Shaker Church building was constructed above the bay c. 1890, Mud Bay being the home of the founder Sam "Mud Bay Sam" Yowaluch, the first Bishop of the church (see List of Indian Shaker Church buildings in Washington § Mud Bay church).