'Harborage' was a US operation within 'Alsos' and 'Big' during the last weeks of World War II to search and extract from the cities of Hechingen, Bisingen and Haigerloch in the south-western part of Germany all possible information and equipment related to the German nuclear weapons programme (April/May 1945).

These cities lay in the area which was to be occupied by French troops, and the operation effectively denied the French any easy entry into the development of their own nuclear weapons, and also any involvement in the lively post-war 'trade' in German nuclear scientists.