If you’ve viewed our school on Google Maps or Google Earth, you might have noticed the numbers “31-713” on the MTHS roof. Why are they there? What are they for?

Well, according to Sheriff Robert Trenary of the Snohomish County Sheriff’s Department, they’re actually obsolete. Sheriff Trenary says the numbers were installed after the September 11, 2001 terrorist attacks to allow police and medical helicopters, and other aircraft, to spot and identify the school easily from the air.

This ability to easily identify the school building from high altitudes may have come in handy if a medical airlift needed to pick someone up, or if the police department needed to give aerial support in the event of a catastrophe, including a school violence scenario.

Randy Fay of the Snohomish County Department of Emergency Management also added that the installation of the numbers was paid for by a federal grant. The numbers were then maintained by the school district. However, with the introduction of GPS technology, the numbers became obsolete—but they remain on the roof to this day.