Found around: ( 74, -2, 1245 ) Copy/waypoint 74, -2, 1245, ( 184, 1, 1330 ) Copy/waypoint 184, 1, 1330 and ( 406, 12, -509 ) Copy/waypoint 406, 12, -509. Most of the monsters at these locations place-hold for each other, so if a mature antelope isn't up, then keep clearing creatures in these areas and one will eventually spawn.
Wanders in the Griffon areas, at the north end near The Mirror, and at the south end, just near the entrance to Deadview Pass.