Officially called the Magdalena Stock Driveway Shipping Pens.

These pens were built in 1885 when the Atchison, Topeka and Santa Fe Railway completed its branch line
from Socorro to Magdalena. Stockmen from as far away as Springerville, AZ and Reserve, NM drove their
cattle and sheep to Magdalena for shipping to the markets back east. Records for 1910 show 21,677
cattle and 150,000 sheep were shipped from these pens. The use of the Stock Driveway declined in the
1960s as trucking increased. It came to a halt in 1971 when the Santa Fe Railroad closed the line. The
Driveway was disbanded shortly thereafter.

There's so little left of the 'old west' that it's fascinating when you discover a bit of it still remaining.

Photographed in Magdalena, New Mexico USA.