Waypoint 16: (N32.01371 W112.69843)
To the left of the trail is a pine-needle milkweed (Asclepias linaria), so-called because of the resemblance of the branches to pine branches. Like others in the milkweed family, this species is strongly favored as a source of food by butterflies. This species occurs in this area only at relatively high elevations and is not down on the desert floor.
The spectacular view to the west includes the Bates Mountains with Kino Peak, the Granite Mountains far off in the distance in the Cabeza Prieta Wildlife Refuge, and the Growler Mountains near the east end of the Refuge.
Waypoint 17: (N32.01363 W112.69877)
Here the trail goes through a layer of obsidian. Obsidian is a form of volcanic glass, usually black in color. More pure forms of obsidian are clear enough to see light shine through thin samples. In this region, obsidian often contains "marbles" varying in size from 3/8 inch to 1 inch in diameter. The process of formation of these marbles is unclear. To the left is a jumping bean (Sebastiania bilocularis), most easily identified in the winter because of the red leaves. Jumping bean occurs from mountain regions like this down into desert bajadas mostly along washes.
Bull Pasture Overlook: (N32.01437 W112.69812)
The overlook marks the end of the Bull Pasture trail as such. However the trail continues on to the summit of Mt. Ajo, another 1550 feet higher. Ahead, across the small wash, is the actual Bull Pasture. The Pasture contains an intermittent spring marked by an area of thick vegetation. In the distance (perhaps a mile away) at the east end of the Pasture where the trail heads on up to the main Ajo Mountain ridge can be seen an area of gray tepee-shaped formations. These formations, called the "the Cones" are formed from volcanic ash that didn't become welded into hard stone, and so, are easily eroded.