Collected along the Columbia River probably on 30 or 31 Oct 1805 as Pursh gives the location as "On the great rapids of the Columbia river" and the herbarium label has "Octbr: 1805." This implies that the specimen was gathered when the expedition was along the Columbia in either Skamania Co., Washington, or Hood River Co., Oregon. Clark observed several trees on 30 Oct (Moulton, 1988: 358), but no maple is mentioned. On 12 Apr 1806, Lewis refers to "a species of maple" which Moulton (1991: 112, 114) takes to be Acer circinatum. Lewis illustrates and describes the species on 10 Feb 1806 while the expedition wintered-over at Fort Clatsop, Clatsop Co., Oregon (Moulton, 1990: 294-295). (The Lewis & Clark Herbarium Digital Imagery Study Set, ANSP, 2002) On deposit at the Academy of Natural Sciences, Philadelphia Collected by:Meriwether Lewis & William Clark Collection date:10/30/1805