Title: Duncan Rocks, Straits of Juan de Fuca; Washington. Letter from the Secretary of War, transmitting, with a letter from the Chief of Engineers, report of examination of Duncan Rocks, Straits of Juan de Fuca, Washington
Subjects: Hydrography, Topographical surveying
Places: Juan de Fuca, Strait of (B.C. and Wash.), Strait of (B.C. and Wash.) Juan de Fuca