In the 1890’s, there was only a one-room school serving the area of Diamond Bar and Walnut. The original location was on Lemon Avenue in Walnut where the Ron Hockwalt Academies are today.  The first superintendent (who was also the principal) and the school custodian (who was also the bus driver) lived in a duplex on site.  Later the original structure was replaced with four classrooms.

Until Diamond Bar Ranch was sold and the Walnut area around Mt. San Antonio College and the south end of Diamond Bar was developed, the surroundings were rural fields and citrus groves. Down the street was a citrus-packing plant. In 1959 there were about 200 students.

As our communities grew from the days of ranchers and farmers, so did the need for additional schools! 

In the 1960’s, Walnut Valley was a K-8 elementary school district with original schools Suzanne Middle School, Castle Rock, Collegewood, Evergreen, Vejar, and former Walnut Elementary campus (now Ron Hockwalt Academies).

In 1968, the La Puente High School District built Walnut High School, and paved the way for an election to form the new Walnut Valley Unified School District.

In 1970, the Walnut Valley Unified School District was created as a unified school district for students from kindergarten through twelfth grade.

In the past four decades enrollment has gone from 4800 students on eight campuses to nearly 15,000 students on 15 campuses in Diamond Bar and Walnut! 

Today the District is ranked as one of the best in the San Gabriel Valley.  Thirteen of the 15 schools are California Distinguished Schools. Walnut and Diamond Bar High Schools have the International Baccalaureate (IB) Diploma Program. C. J. Morris and Castle Rock Elementary Schools have the Primary Years International Baccalaureate Program.

US News and World Report ranked Walnut High and Diamond Bar High amongst the top high schools in the country for 2008, 2009, and 2010.  Newsweek ranked DBHS and WHS amongst the top 500 public high schools based on how hard school staffs work to challenge students with advanced-placement college-level courses and tests.

A 99% graduation rate (2010) of 1571 seniors  Over 90% of graduates attending four-year or community colleges California API scores above 800 for all schools with 8 exceeding 900 The San Gabriel Valley Tribune’s rating as the highest achieving school district in the San Gabriel Valley