Helicopters on Mars may sound like something from a science fiction novel — or perhaps just a typical "Doctor Who" episode. But actually, they're not fully confined to the world of sci-fi; after all, ...

Anyone who has ever paddled through the flooded forest at Chatfield Reservoir or just spotted it from the shore would notice the trees that line the area. Next time recreators visit the reservoir, ...

In the forests and canyons of the Northwestern US, helicopters are now doing something that would have horrified river engineers a generation ago: dropping thousands of tree trunks straight into the ...