The process of making maple syrup is an age-old tradition of the First Nations people, who used it both as a food and a medicine. They would make incisions into trees with their tomahawks and use birch bark containers to collect the sap. The sap could be reduced into syrup by evaporating the excess water by plunging hot stones into the sap. They also increased the sugar content by removing the frozen water layer after the nightly freezing of the sap. When the settlers came to North America, they learned from the Natives that sap could be made into sugar. They used their iron tools to tap the trees and then boiled the sap in the iron kettles. Maple syrup was the preferred sweetener used by the early settlers since sugar from the West Indies was highly taxed and very expensive. As sugar became less expensive, it began to replace maple syrup as a relied-upon sweetener. Maple syrup production is now approximately one-fifth of what it was in the beginning of the 20th century. In Canada, sugar maples are only found in select regions.