In 1878, a sod school house was built where the Lerton Cemetery now lays. This was a small one room sod house where school, Sunday school, and church services were held. A larger log and sod house was built in 1880 south of the Catholic cemetry.

    A white school, known as the Mound School, was erected in 1882, one mile east and 1/2 mile south of the present Giltner school house corner. Later it was moved into Giltner and stood by the new school house and eventually sold to the Free Methodists for a church.

    After the town of Giltner was started in 1885, a larger school house was built, between Dr. P.O. Marvel's home and the Methodist church, not far from the center of town. This was a common eight grade school with a basement and two rooms, one upstairs and one on the ground floor. At first only one room was used. The school did not have separate grades; older and younger students were all together. Mr Ezra Simons was the teacher. A stove was used for hesating purposes. Later two more rooms were used.

    In 1907, two more rooms were added to the back of the 1885 building, the lower of which was used for primary grades and the upper for high school assembly. An 11th grade was added in 1909; then the 12th grade was added 1913. The school was accredited so the Giltner students were then eligible to enter any college or university in the United States upon graduating from Giltner as it was a standard twelve grade school.

    A large two story brick building with a basement was built in 1917. It was a modern twelve grade school. The building contained a gymnasium and an assembly room with a stage.

    A major addition was made to the Giltner school in March 1956, which is still in use today. The new facilities included kindergarten through third grade classrooms, office, shop, kitchen, with a serving access window to the new auditorium that had fold away tables on the west wall, permanent bleachers on the south side of the gym and a large stage on the north.

    The present school building was dedicated on April 12, 1981. Use of the 1917 building was discontinued then torn down. Since 1981, there has been many upkeep and improvement projects to the school-a greenhouse that was added to the north side of the school in 2004, with the north end of it used for the concession stand, during football games (this was possible due to the generosity of an anonymous donor); new playground equipment, paid for and installed by the Booster Club, who also constrcted a new press-box for the football field in 2009; and a modular classroom was purchased by the school from the Aurora schools to be rented for use as a preschool/daycare center. The "Hornet Prep" was ready for business in late summer of 2009. This was made possible due to the help of the Giltner Area Development Corporation members and other volunteers.