One of the buildings present on the Grundy County Museum grounds is a one-room school called Colfax No. 3. Country schools were named and numbered according to their placement in the Township where they were located. This school was located in Colfax Township, Grundy County, Iowa. The number three indicates that it was located in the northwestern corner of the Township. The school is one of the earliest in Grundy County being constructed in the late 1870's. It served a fledging Luthern congregation for a time and as was typical of many country schools served as a social center, as well. The building was moved to the grounds, restored, and is furnished to the 1880-1900 period. It is used by area school classes for 1/2 and full day learning experiences.