According to the label Lewis collected the lectotype on 1 Jul 1806. On 2 Jul, however, Lewis "found serveral other uncommon plants specemines of which I preserved" (Moulton, 1993: 79). Moulton (1993: 81) suggests Orthocarpus tenuifolius was one of these. Pursh says the plant was found in July on "the banks of Clarck's river," the name Lewis used for the present Bitterroot River. This conforms with "Valley of Clark's R." on the specimen label. Lewis presumably gathered the plant in the Bitterroot Valley in the vicinity of Traveler's Rest, the location of their campsite on 1-2 Jul. (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:07/01/1806