The USAF Academy's Eisenhower GC has two superb 18 hole courses and only available to active duty military, retired, student, contractor, et. al, or a guest of one of these. It's located off I-25, Exit 156/USAF Academy North entrance, then west. Both courses are rated as one of the top courses in the US Military, and are the most reasonably priced courses of this quality you can play in Colorado.
The Blue course can play to 7,300 yards from the Falcon tees, 134/72.6, course/slope ratings and was designed by Robert Trent Jones in 1963. It's the most challenging of the two with long holes, wide open fairways, doglegs, bunkers, and good sized greens with water in play on one hole.
The Silver course is easier on your game and shorter with a light amount of bunkering and water in play on three holes. Accuracy is more rewarded here than length, especially around the greens, the course measures 6,519 yards from the championship tees and 5,215 from the forward tees and was designed in 1977 by Frank Hummel.