Leon Slichter, Idaho County Noxious Weed Control, explain that this Common Crupina infestation site is on the Rice Creek grade on the way to the Joseph Plains, immediately south of Cottonwood about 12 air miles. The Joseph Plains was named after Chief Joseph, who was actually from Oregon, but General Howard chased Joseph and his Nez Perce tribe here during the Nez Perce war.
Note that there are several video "hot spots" available which provide a lot more detailed information.
Panorama and video taken 6/9/06