Mast is the fruit, nuts, and seeds of trees and shrubs that falls directly to the ground and is not scattered by the wind. Hard mast has a hard exterior, such as beechnuts, walnuts, and acorns. Soft mast has a fleshy exterior and includes black cherry, sassafras, grapes, apples, and blackberries. Mast production varies widely by species, location, and year, and especially by weather. Mast was an important factor in agricultural production in West Virginia in earlier times, when mountain farmers allowed their hogs to forage in the forest. Mountaineers also depended on the game fed by mast, and consumed mast directly as nuts, wild fruits, and berries.

Because a greater percentage of West Virginia is forested than surrounding states, our wildlife species are more dependent upon mast for food. The most important mast species for wildlife are the oaks, which may produce more than 700 pounds of acorns per acre in good seed years. Acorns comprise about 70 percent of the fox squirrel's diet, 37 percent for turkeys, 54 percent for deer, and anywhere from 10 percent to 50 percent for ruffed grouse, blue jays, black bear, raccoon, wood ducks, and nuthatches. Wildlife biologists annually rate mast abundance which they use to predict wildlife abundance and subsequent game harvests.

It is believed that the devastation of the American chestnut by the chestnut blight severely affected wildlife populations in the state. In many areas of West Virginia chestnut was the dominant species and was a substantial component of the diet of wildlife. Current mast production is thought to be significantly less without the American chestnut as oaks typically have sporadic seed years.