Our local camas prairies were naturally formed about 14,000 years ago after glaciers retreated. Foods, including edible roots and berries, thrived in this open landscape. Eventually, this habitat would have disappeared as trees moved in and created forest. Plants that were dependent on sun and well-drained soil would have disappeared. Northwest Coastal People learned that burning prairie areas every few years would kill tree saplings and promote the growth of edible food plants. Deer, elk and other animals grazed on prairie grasses and berries. Not only did the prairie plants feed people, and animals, but the open areas also made hunting easier.
Special techniques of harvesting and pruning berries and other foods were utilized to increase the bounty of prairie plants. Examples include bulbs like camas and chocolate lily, which were thinned to make bulbs bigger and more delicious. Native gardening techniques were often mutually beneficial for plants, people and animals. Without those techniques, prairie plants may well have disappeared from the Northwest long ago.