There are 9 species of blueberries / huckleberries in California. Some ripen mid-summer to late September, and others ripen from early fall through mid-winter.
The sweetest and juiciest are found in full sun. These fruits were a favorite of the California Indians, who would make long treks to choice picking grounds. They would dry the berries, mash them, and form cakes of them for storage. They were also often used mixed with dried and powdered venison jerky and melted suet fat to form pemmican; the original energy bar.
Blueberry fruits also make excellent blue / purple dye.