In 1964 the USC&GS Surveyor crossed the Aleutian trench 48 times between 165° and 180°W longitude. The data provide a basis for a free-air gravity map, a Bouguer gravity map (density 2.87 gm/cm3), and three possible crustal models that fit the results and available seismic data. The area covered lies west of an earlier gravity survey described by Peter, et al.  of the Aleutian trench between 155°W and 165° longitude and 53° and 55°N latitude. As on the earlier gravity survey, which was also carried out by the U.S. Coast and Geodetic Survey, the observations were made along north-south lines spaced 20 km apart and extending about 200 km south of the island arc.