The William S. Hart Union High School District Governing Board unanimously approved the appointment of Valerie Van Oss as the new Director of Fiscal Services and Mark Overdevest as the new assistant principal at Valencia High School.

“We are pleased to welcome Ms. Van Oss and Mr. Overdevest to their new positions in the district,” said Michael Vierra, Interim Superintendent of the Hart School District. “Each brings with them the advantage of considerable years of successful experience within the Hart District. We look forward to seeing the positive impact of their work to support our students, staff and families.”

Van Oss began her career in the Hart District in 2011 as a payroll technician, assuming similar payroll positions after a move to Washington in 2012. Ms. Van Oss returned to the Hart District in 2017 and has served in the positions of payroll technician and accountant/internal auditor before her most recent assignment in 2021 as Manager of Fiscal Services. Van Oss has a Bachelor of Arts in Business Administration from California State University Fullerton.

Overdevest began his career in education as a physical education teacher in the Hart District in 1996. He has worked at a variety of schools and levels, including Arroyo Seco and La Mesa junior high schools and Saugus and Castaic high schools. Overdevest has also served in a number of roles at those sites, including department chairperson, technology coordinator, staff development team member, ASB director and athletic director. He has a Bachelor of Arts in Kinesiology Exercise Science and Physical Education from California State University, Northridge and a Master’s in Cross Cultural Teaching from National University.

Both officially began their new roles on Sept. 12