The first school in Walnut began operations in 1872. In 1875 the school had 25 students; that year its first permanent building, with a cost of $5,000, opened; it was destroyed in a fire in 1913. A replacement building opened later and served as the school building into the 21st century. The current building opened in 1910 the Walnut School opened. In the 1950s the Walnut School building received an addition on its north side. There were other additions. In 2012 the Walnut district and the
A-H-S-T Community School District began partial-day-sharing, in which students went to one school for some courses, as well as sharing of athletic programs. In 2014 the district began whole grade-sharing, in one school district sent its children to another school district to attend schools there all day. In 2015 A-H-S-T was three times larger than Walnut. If the Walnut district did not merge, in the following school years its spending could have increased beyond the amount permissible under Iowa law. In the 2015–2016 school year the district had 72 students. The prospective combined enrollment was to be around 770 students. ==References==