The Tortugas Mt. Observatory is located just east of Las Cruces, and houses a 24-inch Boller and Chivens telescope (for some more information on B&C telescopes, see http://bollerandchivens.com) . The telescope was built in the late 1960's and used extensively up until the early 90's, mostly for planetary monitoring. After that time, the telescope fell into disuse, perhaps because the NMSU Department of Astronomy started to operate the Apache Point Observatory, which is home to a set of significantly larger telescopes.
Starting in 2010, NMSU entered into a MOU with the American Association of Variable Star Observers to get the telescope back into operation again. This has involved significant technical upgrades to the telescope, but the process is going well!