The discovery that many of the objects made by the Tlingit Indians in Alaska are of native copper rather than exclusively of European copper, is used as evidence of communication between various groups of people ranging from Greenland to Siberia. Further evidence for this is the combination in objects of native copper and musk-ox horns. The latter come from farther away than the already known source of copper (the near-by Copper River Basin). In addition, there are trace elements in some of the native copper objects which are not found in the Copper River Basin metal. The varying physical properties of native and other copper are described. The native copper shows no evidence of stress-hardening, hammering or annealing, or of being worked in a forge. It is pure and has large crystals. The objects, such as daggers, rattles, masks, were worked with stone saws and were successfully protected by a coating of fish-oil. The article is copiously illustrated. -- AATA