Some confirmed locs for its spawn are

• ( 924, 185, -2109 ) /waypoint 924, 185, -2109
• ( 998, 127, -2268 ) /waypoint 998, 127, -2268
• ( 959, 170, -2145 ) /waypoint 959, 170, -2145
• ( 968, 170, -2121 ) /waypoint 968, 170, -2121
• ( 985, 149, -2216 ) /waypoint 985, 149, -2216
• ( 1130, 144, -2072 ) /waypoint 1130, 144, -2072

Using a Gnomish Divining Rod won't be of any use. I had to search inside the circle of trees using First Person view.