Here Mike, see if this helps. It looks better from where I originally spotted it, but had to get close to get photos. It's about 14' tall at the peak I guess. You'll notice the face and "legs" are of darker stone than the rest of the rock. That's what stuck out at me, plus the "eyes".
If it's large and meant-to-be-something, then it should be noticeable from at least one or two points a good distance away. How far? I have no idea, but if there are any other high points, say within a quarter-to-half-mile away, I'd take a walk and a gander to see what it looks like from those points. I'd also be looking for old wagon roads/horse trails within a half-mile circumference.
Randy, its a monument for sure, possible trails shown in different directions, main Mission direction may be toward the direction the head is pointing, I have been trying to get someone to measure the distance between monument and Mission but sofar not one answer, possible deadly trail, no water, turtle to me indicates slow,and long trail carry plenty of supplies, the distance could be as far as 25 miles ( 2.5 leagues X 10 ) . Thats just my guess, I think they used a Mission as a hub and started in a predetermened direction where they had mines and at that point the trails seperated into different directions / distances to the mines / trails. from there you should be able to pick up trail markers, chesk from where the tail points to other monuments 25 miles away. Its really not that complicated. If I don't get any information back to verfiy what I think they represent then I will go the way of lost horse and other, its your call