The trail past Green Lake and up Glines Canyon is currently clearly marked. After following the sign for West Lake at the first junction, the trail passes a campsite after 200 yards, does a quick switchback up the hill, and shortly comes to a second sign noting Green Lake to the left and West Lake to the right. Head left.
Also I do not believe the trail is just a use trail- perhaps a no longer maintained one? Though overgrown in a few spots there are places where limbs have been cut so they are no longer blocking the trail, and the switchbacks through the talus to Virginia Pass appear constructed.