Because of the size I would try measurements of KM, the open mouth is a direction and V has a value of 22th letter of the alphabet and also it has in some instances indicate roman numeral = 5 / mouth go this way / can also be measured in leagues, I would look in the direction of the face for 5 leagues or 12.5 miles, first if its possible check the area for a spanish mission, possible as far in reverse as 12.5 miles, see if its 25 miles between missions and if its 30 degrees there may be something of interest for several folks on this thread Thanks and good luck
There may have been a Mission near there at one time, if its possible you may check in the reverse for possible Cache sites, the 1st indicator that I would look for a cache site would be an area aprox 400 feet square with between 10 and 30 symbols ( rock carvings ) small / large mounments, a diamond or a triangle indicating where you are at in the trail, middle / start / end of the trail, there may be a triangle carving near the head, a cross with a broken arm, or anything that would indicate three, I would start looking reverse of the head and check at least 1/2 mile near a feature that would draw your attention