The U.S. Air Force thinks the rough-hewn peaks of southwest Colorado and northern New Mexico make excellent surrogates for the treacherous mountain ranges in global hotspots such as Afghanistan. Some local residents beg to differ.

In a bid to provide Special Operations pilots more realistic simulations of wartime missions, the Air Force has proposed a vast new tactical training zone that stretches across 94,000 square miles of rugged terrain. Starting next year, commanders want to send C-130 transport planes and CV-22 Osprey...