Idaho was the first state to start building, and Todd's second volume says it was also the first to finish. The Official Guide says the first to finish and dedicate, and Todd's chronicle of 1914 agrees that it was dedicated in May of that year; its formal dedication in the season came on March 25, 1915, a month after Ohio's. It was a simple building in good taste, two stories of "travertine" with end pavilions, about 50 by 150 feet. It faced the Marina with a view of the bay and the mountains. It had rooms for visitors from Idaho, a motion-picture theater, and special accommodation for the state's school teachers, the only State building that offered it.
On Idaho Day, September 29, 1915, Governor Moses Alexander planted a fir. Its ceremonial tree was one of 33 planted at State and foreign buildings during the fair and moved to Golden Gate Park early in 1916 as the Exposition Grove (Todd vol. 3, ch. LXXXVI).