Roger Batt, with the Idaho Weed Awareness Campaign explains that they are in the Lower Hulls Gulch Reserve and are looking at a pretty good stand of Poison Hemlock. Bryan Dallolio, Ada County Weed Control, further explains that Poison Hemlock is a poisonous plant and they have problems with this plant not only in this reserve, but also in areas that might be grazed. They would like to see some sort of protection for valuable animals from this plant.
Note that there are several video "hot spots" available which provide a lot more detailed information.
Panorama and video taken 5/31/06