The Norse began exploring North America in the late 10th century. Voyages from Iceland reached Greenland, where colonists founded settlements along its western coast. Norse settlements on Greenland lasted almost 500 years and reached a total population of around 2,000–3,000 people. These settlements consisted mostly of farms along Greenland's scattered coastal fjords. Norse colonists relied heavily on hunting, especially of walruses and the harp seal. For lumber, they harvested driftwood, imported wood from Europe, and sailed to modern-day Canada. Archaeological evidence indicates that the Greenland settlers used lumber and possibly iron ore imported from North America.