Look at a wooded hillside.
Tree map: Program catalogs every grove in the U.S. forest
Single out a grove of trees about the size of a couple of basketball courts. Hike up there and count every tree in that space, measure its height, check its health and record all the results.
Repeat 2.8 billion times.
Or call up the Forest Service Rocky Mountain Research Station and borrow their new Tree Map. In a 21st-century version of seeing the forest for the trees, a team of fire researchers in Missoula have crunched all those pixels of satellite data to inventory the woods covering nearly a third of the Continental United States.
“Lots of other people have tried to do this with limited success,” said Karin Riley, one of the researchers who helped develop the Tree Map. “When we started embarking on this, a lot of them told us we would fail. It’s a really hard problem.”