Meriwether Lewis observed this tree leaf, later identified as a vine maple, in the Columbia River area. "The leaf is petiolate, plane, scattered, palmate lobate, divided by four deep sinuses," Lewis wrote on Feb. 10, 1806.
Lewis and Clark braved the unknown waters of the Missouri to chart America's future. As we approach the 200th anniversary of their sojourn, TIME reflects upon their sacrifice and achievement
Vine Maple Leaf