Koehler, who retired from the Army as a lieutenant colonel in June 2009, arrived at the Academy in 2001 as one of the lacrosse program's military coaches. Since his arrival, the Falcons have allowed their opponents to average less than nine goals per game in six seasons, including 2004, when Air Force allowed just 7.94 goals per contest.
As the Falcons' mentor on the defensive end of the field, Koehler helped guide the Falcons to a 7-7 overall ledger in 2009, including a 4-1 record in the Great Western Lacrosse League and a second-place conference finish. While the team finished at .500 for the first time since 1997, the Falcons' four league wins were also a school-record. In 2009, Air Force allowed just 8.93 goals per contest, while sophomore goalkeeper Brian Wilson ranked among the league leaders with a 7.91 goals against average. Meanwhile, in 2011, the Falcons allowed just 8.62 goals per game en route to a 6-7 overall record.
A 1985 graduate of the United States Military Academy, Koehler was honored with the General George Ruhlen Award (Most Improved) in 1984 and the General James V. Hartinger Award (Most Valuable Player) in 1985. Koehler was also an honorable All-America goalkeeper in his senior campaign.
Following his graduation from West Point, Koehler was commissioned as a second lieutenant in Field Artillery. His first permanent assignment was at Fort Carson, Colo., where he spent four years as a fire support officer and a fire direction officer. He then spent nine months at the Army's Defense Language Institute in Monterey, Calif., where he studied German, and also graduated from Ranger school at Fort Benning, Ga., before spending two years in Baumholder, Germany, where he commanded an artillery battery of over 125 soldiers.
After returning from Germany, Koehler earned his master's degree in kinesiology at Indiana University and then returned to West Point to teach in the physical education department. While at West Point, he also served as the volunteer assistant lacrosse coach for three years.
Before coming to the Academy, Koehler was stationed at Fort Hood, Texas, for two years. He served in the 1st Cavalry Division where he deployed to Bosnia for six months and Kuwait for a month.