An oak savanna is a type of savanna, or lightly forested grassland, where oaks are the dominant tree species. Although there are pockets of oak savanna almost anywhere in North America where oaks are present, there are three major oak savanna areas: 1) California and Oregon in the west; 2) Southwestern United States and Mexico; and 3) the prairie/forest border of the Midwest. This image is from the Oregon variety on Sauvie Island, Oregon.