Great find!!
On what we now call Coronado Mesa?
Or surrounding canyon walls?
(Been looking for a cross on Coronado Mesa, once allegedly called Cross Mesa, though there are no US records that indicate that)
Garrett atx pi 12+20inch coil, Garrett mh series, Garrett 2500+t-hound attchmnt, fisher tw-6 two box, Pulsestar pro ii with various coils up to 98 inches, pulsemaster pro w/1.2 m coil
I know of one that the hooked or flourished part of the X line points to the mine... So I would look a ways straight up from it. And yes, it's done as a natural looking "X" in cracks in the rock strata along a trail....
The one I know of is about 200 feet from the mine (can't remember exact distance), the mine being uphill from the X.