Tucked away in the rolling hills of northern Michigan a once-dilapidated warehouse in the town of Copemish now brims with thousands of tiny saplings. But these trees are not as young as their sizes would suggest. A nonprofit, Archangel Ancient Tree Archive, has cloned from tissue samples of some of the world’s oldest and largest trees found across the U.S. and beyond—some more than two millennia old.

“Most coast redwoods and other trees don’t live to be a thousand years old, but some live to be 2,000 or more and we don’t know why,” says David Milarch, lifelong nurseryman who co-founded the Champion Tree Project in 1994, which became Archangel 14 years later. But deforestation has rapidly decimated old-growth forests and has done so before scientists got much of a chance to study the genomes and even the ecology of such “champion trees.” In the U.S. only about 2 percent of its old-growth forests remain.

Milarch uses the saplings to act as “living archives” to create or rehabilitate forests. Archangel supplies a loose network of environmental organizations whose volunteers do the planting. The organization has planted tens of thousands of quasi-ancient trees in the U.S. as well as six other countries as faraway as New Zealand and France.

Their latest major planting effort shipped 1,000 coast redwood saplings to Port Orford, Ore., in early February. The last of them went into the ground last week. Volunteers helped Archangel sustainable development consultant Terry Mock plant the trees in parks, private estates and elsewhere along a 160-kilometer stretch of the Oregon coast. They chose to plant the trees north of the current range of coast redwoods as an assisted migration effort, Mock says. Forests move very slowly but many species of trees, including coast redwoods, are unlikely to be able to survive in their current range as the climate continues to change. Planting trees where suitable climate is shifting to could give forests the head start they need.

Using propagation techniques (see slide show for more details), Archangel has cloned ancient coast redwoods, sequoias, oaks and more than 150 other tree species, preserving their genetics in the process. This could be accomplished by filing away DNA samples but the mission of the archive extends beyond genetic preservation into expansion of living forests.