The Washburn Tunnel is a two lane underwater roadway connecting Galena Park and Pasadena. Named after Harris County Auditor Harry L. Washburn, the tunnel opened in 1950. It is the south's largest and first toll-free vehicular tunnel. The site was added to the National Register of Historic Places in 2008.
Located under the Houston Ship Channel in east Harris County, the tunnel is 2,936 feet (about ½ mile) long with a 6% grade. The total width of the roadway is 22 feet with each lane being 10 feet wide.