The Army wants train with drones and other new equipment at the Piñon Canyon Maneuver Site east of Trinidad and has put in formal notice to seek a new Environmental Impact Statement for the 235,000-acre training area.
The filing Tuesday in the Federal Register says the Army will seek to restrict air space above the site to accommodate helicopter and drone training as well as the use of new targeting and jamming gear.
"Advances in equipment and weapons systems, to include their incorporation into tactical units, dictate changes in how the Army trains, alterations to ranges (including range airspace) for maneuver training and doctrinal changes to accommodate mission-essential training prior to global deployments," the Army said in the notice.
In the past, the Army has used small drones, which fly at low altitudes, in Piñon Canyon training exercises. Using larger, high-flying drones and other aircraft would require closing the airspace above the site to civilian air traffic.
"This reclassification is required to conduct integrated and realistic air and land training and to accommodate high-angle, indirect-fire weapon systems and airborne laser target sighting system training," the Army said.
The Army now has closed airspace over Fort Carson for drone flights and the Air Force Academy has closed air space for drone training.
The notice says the Army will keep its 30-year-old promise to not use explosives on the site, but would continue to use machine guns and inert rocket rounds.
The Army also expressed interest in adding staff and buildings to the training area.
The move comes months after the Army put a bullet in earlier plans to expand the site.
Beginning in 2004, the Army pushed to grow Piñon Canyon, asking for an additional 100,000 acres of ranchland in the sparsely-populated region.
Ranchers in the area, though, teamed with environmental and anti-war advocates to form a powerful coalition that blocked the Army's attempts.
In a deal brokered by Colorado's Democratic Sen. Mark Udall, the Defense Department in November revoked its permission for the Army to seek more land.
The Army at that time pledged to conduct its training on land it already owns and to be a better neighbor.
Even with expansion off the table, the Army's move to close air space over the canyon is likely to spark controversy. The military plans meetings on the change in Trinidad and La Junta to take comments. Dates of those meetings haven't been released.
"The proposed action could have significant impacts to airspace, soil erosion, wildfire management, cultural resources, and water resources," The Army said. "Mitigation measures will be identified for adverse impacts."