During World War II, the island was closed to tourists and used for military training facilities. Catalina's steamships were expropriated for use as troop transports, the U.S. Maritime Service set up a training facility in Avalon, the Coast Guard had training at Two Harbors, the Army Signal Corp maintained a radar station in the interior, and the Office of Strategic Services (a precursor to the CIA) did training at Toyon Bay. Emerald Bay, on the Island's west end was used by the Navy.