The Alpena CRTC boasts the largest airspace east of the Mississippi River , has 147,000 acres available for ground maneuver units .
The Alpena CRTC trains over 20,000 joint and coalition personnel annually .
The Alpena CRTC boasts the largest airspace east of the Mississippi River , has 147,000 acres available for ground maneuver units , and trains over 20,000 joint and coalition personnel annually .