That area is probably close to where you have hunted. May be worth a day's trip to scout around.
You have found many of those 1/4 real state coppers from Chihuahua.
This type was issued in 1860, '61, '65 and '66.
The smaller coin is a 5 centavos Chihuahua 'Republica Mexicana' coin of which there were two types.
The first (1868-1870) has a small '5' above the word Centavos on the reverse. The other type (more common) has a large '5' with Centavos shown below the '5'. Its issue dates were between 1871 and 1895. (with the exception of 1872 and 1875--for some unknown reason).
Don in SoCal