Until the beginning of the 2Oth century, American chestnut trees dominated forests in the Eastern United States, making up one in four trees found from Maine to Florida and west into the Ohio valley.

But the majestic giants -- up to 100 feet (30.5 metres) tall and 5 feet (1.5 metre) in diameter -- were nearly exterminated by an Asian fungus imported on plants.

The fungus was discovered in New York City in 1904 and quickly spread, killing some 3.5 billion of the trees by 1950.

Government-paid workers in the Civilian Conservation Corps during the Depression in the 1930s built cabins and lodges with the dead trees at public campgrounds, many of which still stand today.

Because it grows straight and is free of branches in its lower half, the chestnut was favored for timber and was used for telegraph poles, railroad ties, paneling, fine furniture and musical instruments.

CHINESE HYBRID

Millions of chestnut sprouts continually pop up from the ground where the trees once stood, but the vast majority get killed by the fungus before they can produce nuts.

To bring the species back, scientists over several generations bred the American chestnut with the blight-resistant Chinese chestnut tree. Now, after 25 years of efforts, scientists at a breeding orchard in Virginia and Penn State University are producing seeds and seedlings to replant.

The latest generation of hybrid trees have almost 95 percent of the American chestnut genes along with the blight-fighting power of the Chinese chestnut.

"In planting this tree, we are planting the hope and making a commitment that this noble hardwood will be restored to the American landscape and its vital ecological role in our nation's forests," Kempthorne said.

Kempthorne said the government would work with the coal mining industry to plant the trees on reclaimed mine sites in the Appalachian Mountains, where the loosely packed soils allow them to take root quickly.

The hope is that nearby wildlife will then spread the trees to neighboring forests.