On back of the photograph:
THE BOEING BB-L6 OF 1920
This airplane, a three-place open cockpit sports biplane built for Herbert Munter, a pioneer Northwest aviator, was a wood and fabric construction with demountable dual controls. Hunter, now vice president of West Coast Airlines, used it in making the first flight over 14,408-foot Mount Rainier. Boeing in 1920 also built 111 DH-4B two-place open-cockpit observation biplanes for the U.S. Army.
Wing span 44' 9"; length 29' 3"; weight 2,632 lbs; speed 100 mph; ceiling 15,000 ft.; range 450 mi.; power, Hall-Scott L-6 (214 hp).