From the Howard Cannon Photograph Collection (PH-00192). Stamped on verso: "Photo by: Ankers Capitol Photographers 316 F Street, N.E. Wash., D.C. 20002 Phone (202)543-2484", possibly members of the Aero Club of Washington, D.C.
A section of Howard Hughes' "Spruce Goose" or "Flying Boat" being moved (with a police escort) from the Hughes Aircraft plant in Culver City, California to Terminal Island in the Los Angeles Harbor where the plane was assembled in June of 1946.