On July 8, 2005, Roger Batt, Idaho Weed Awareness Campaign Coordinator, and Bryan Dallolio, Ada County Noxious Weed Control, are standing in a good patch of Perennial Pepperweed, or what some people call "tall whitetop". Bryan notes that this plant has a creeping root stalk and is a lot like Canada Thistle in that it crowds out other vegetation. This is an area that is next to pasture ground and he fully expects the noxious weed to spread out into the grazing area.
Note that there are several video "hot spots" available which provide a lot more detailed information.
Panorama and video taken 7/8/05