It sounds like a good resource. His household gathers a lot of food and medicine from the desert, so it seems the book has a lot to teach even a fairly experienced desert gatherer.
"the qualities of these bacteria, like the heat of the sun, electricity, or the qualities of metals, are part of the storehouse of knowledge of all men. They are manifestations of the laws of nature, free to all men and reserved exclusively to none." SCOTUS, Funk Bros. Seed Co. v. Kale Inoculant Co.