In the early 1950s the airport was served by the original Frontier Airlines (1950-1986) which flew DC-3's on a route from El Paso to Phoenix that included stops at Las Cruces, Deming, and Lordsburg, NM as well as Clifton, Safford, and Tucson, AZ.
A protected group is a group of people qualified for special protection by a law, policy, or similar authority. In the United States, the term is frequently used in connection with employees and employment.
A Special Interest Group (SIG) is a community within a larger organization with a shared interest in advancing a specific area of knowledge, learning or technology where members cooperate to affect or to produce solutions within their particular field, and may communicate, meet, and organize conferences.