Page 99 - Walks In The Black Range, Vol. 4

Saddler Mine Stope Abandonment Marker (above), the stope (below).
is used. To be a stope, the ore/mineral/etc. must have been excavated from the area to create the hole (vs. a shaft or adit which may be dug to get to a body of ore etc.).
Fluorite was the object of mining at Greenleaf and Sadler, an especially important commodity during the Second World War. That is why the Federal Government built the access road into the area. See New Mexico Bureau of Mines and Mineral Resources Bulletin 21 - Fluorspar Resources of New Mexico - prepared by the US Geological Survey. pp 123 - 142 (Fluorite Ridge Mines) for more information about
this area, including an excellent write-up of the mining and mining history of this site.
The Sadler Mine is the oldest fluorspar mine in the Fluorite Ridge area. It was developed on the Susan No. 1 claim in 1909 by the American Fireman’s Mining Company. Before being abandoned it was operated by several other entities, including G. M. Sadler. Some of the surface structures are still visible at the Sadler Mine (photo follow and in this photo gallery).