In 1903, the booming population of the Boise School District dictated the replacement of Central School, which housed the district's secondary students, with a new high school. The district purchased land on Washington Street, and the new high school was built in the center of the block. The school was a two story structure and, upon its opening, 
board members asserted that this was a building large enough to serve Boise for all time.
In 1908, an east wing was added to the center section. The architecture of this addition was of a more modern design and the outside was white brick rather than the usual red bricks of this period of time. In 1912 the west wing was added, using the same architectural style as was used in the east wing. In 1922, the red brick middle section was replaced with a matching white brick structure with an entryway featuring huge columns. This section included a state of the art auditorium that was used by both the school and the community. The new section had a basement and three floors.


In 1919, the Industrial Arts Building was constructed adjacent to the main building This building housed the Boise High print shop, where, for half a century, much of the District's printing was done.

In 1936 a new gymnasium was built. Students had saved their nickels and dimes and put them in a fund which covered some costs of the structure. The new gym replaced the cracker box located in the basement of the main building. The ceiling in the old gym was so low it interfered with the playing of the game of basketball. The WPA furnished the labor to build the gym.Boise High

In 1957, a new music building was added on the west side of the gym. The two blocks west of the school were purchased in the early 1960's and turned into an athletic complex for practicing football, track and tennis.

In the late 50's and early 60's, Boise became more metropolitan, and students from the Baby Boom generation began to arrive in the city's high schools. Growth on the west bench necessitated construction of a new high school, Borah, in 1958. In 1965, the district's third high school, Capital, opened on Goddard Street in Northwest Boise.

The 1980's were a period of rapid growth in the southeast area of the city, as Boise gained a nationwide reputation as a nice place to raise a family. In the late 80's, Boise High's population began to explode, and enrollments were closed for some classes. At the same time, the old building began to show its age, and the Board of Trustees undertook several studies of possibilities for replacement of the school. Public debate raged for almost three years; a bond issue which had as its key element the refurbishment of the high school failed in Spring, 1993. In 1995, the Board voted to run another bond for the construction of two new junior highs and two new elementary schools and the improvement of many buildings. The February bond election passed, with over 70% of electors voting yes.