The California white oak is common along streams and in moist valleys of California, where it provides shade for livestock. It bears long, slender acorns. The Oregon white oak is found in river valleys and warm, dry areas from central California to southwestern British Columbia. The leaves of the Oregon white oak resemble those of the California white oak, but it has much plumper acorns. The Oregon white oak also grows as a low shrub along the Oregon coast and in mountainous regions.
Red oaks are common in forests of eastern North America.
The northern red oak grows from the southern Appalachians north to Ontario and Nova Scotia, and west into Arkansas and Missouri. It is often found along with two other red oak species, the black oak and the scarlet oak. These three species look similar and even experts sometimes confuse them. All three species usually have leaves with seven or nine lobes. But the leaves of black oaks have yellow hairs on the underside.