The vessel is named after Napa County, one of the member counties of the Golden Gate Bridge, Highway and Transportation District. Napa was purchased in 2009 from Washington State Ferries (along with)[1] and entered service with Golden Gate Transit after a refit.[2] The Napa entered service as a substitute for when that vessel began undergoing an engine replacement in June 2009. After Chinook returned from its refit, Napa went in for a full refitting.
Previously, as Snohomish, it was mothballed for years at the WSF Shipyard at Eagle Harbor, Bainbridge Island. Washington State Ferries announced that she was returned to service in November 2007 to replace on the Keystone-Port Townsend run.