I spent quite a bit of time walking around the prairie. I was impressed that I saw no Scotch Broom or other invasive plants. That's because this preserve has a group of volunteers who keep it rather pristine. When Indians used these prairies, they kept trees and undesirable plants away by burning the prairie. The next Spring the flowers would return. The bulbs of the Camas were an important food source. They would be steamed in underground pits or boiled.
Glacial Heritage Preserve
Thurston County, WA, USA