The downtown area and south Boise was served well by Boise High. The southwest bench area was served by Borah High. There was a need for a third high school in the northwest bench of the city. The new high school was opened in the fall of 1965. The school opened to 1,100 students from both Boise and Borah. Capital was named after the center of government.

Capital is a two-story school with a large auditorium and a large modern gymnasium. There is a nice courtyard in front of the school. The school has had only one major addition and that was in 1970 when the planetarium and a few classrooms were constructed.

The planetarium was named after T. C. Bird who served the District as Superintendent from 1957-69. The planetarium is a busy place serving all the District's schools, plus a special showing at Christmas time. The planetarium is under the direction of Mr. Tom Campbell.