This extract is taken from botanist David Douglas’ journal for 1826, concerning the Willamette region of Oregon (Douglas 1914):
Most parts of the country burned; only on little patches in the valleys and on the flats near the low hills that verdure is to be seen. Some of the natives tell me it is done for the purpose of urging the deer to frequent certain parts, to feed, which they leave unburned, and of course they are easily killed. Others say that is it done in order that they might the better find wild honey and grasshoppers, which doth serve as articles of winter food.
Douglas, David. 1914. Journal kept by David Douglas during his travels in North America, 1823 – 1827. Published by the Royal Horticultural Society. William Wesley and Son, London, England. 364 p.