It’s a well known historical fact that Colonel Paul Tibbets piloted the B-29 that dropped the first atomic bomb on Hiroshima, Japan on August 6, 1945. But did you know the bomber group that trained for “special weapons delivery” at Wendover Air Field was shrouded in secrecy? The government did not admit until well after World War II that the 506th Composite Group had trained at Wendover.
This facility was already in use as a training ground for aerial bombardment by the time
the 506th Composite Group came to the air base on December 17, 1944. Tibbets was looking for a remote, secure place where he could train the handpicked B-29 crews for their top-secret mission. When he looked down from 30,000 feet he declared Wendover “perfect.” (Comedian Bob Hope called the place “Leftover Field” because of its remoteness.) The terrain was as bleak and barren as a desert could be. And with 320 days a year of clear skies, Wendover offered the perfect flying weather and plenty of room for bombing practice.
By 1943, there were over 17,500 military personnel at Wendover. The base had 668 buildings including its own hospital, gym, swimming pool, library chapel and cafeteria. There was also a bowling alley, two movie theaters and 361 housing units. The base also had a mock enemy city near the mountains for bombing practice and life size enemy battleships and other targets on the range.
The pilots began training in fifteen specially modified B-29 Stratofortress bombers. Only Tibbets knew the mission of the 509th Composite Group. This was the first group ever organized, equipped, and trained for atomic warfare. 
by the specially modified B-29s to furnish information on ballistics, electrical fusing and detonators, release mechanisms, and the flying characteristics of the aircraft. Special hydraulic lifts were used to load the huge bombs. Over 155 test units were dropped. Pilots also practiced a 155-degree diving turn, a special maneuver Tibbets designed to shield the planes from the atomic blast.
Many of the original buildings still remain today at Wendover, including the massive hangar which housed the Enola Gay and it is the best preserved bombing training base from World War II.