In 1993, Mary O’Brien purchased two acres of farmland on the Sammamish Plateau, 20 miles east of Seattle and created Arbor Schools. Mary received her Montessori teacher training and credentials from under the tutelage of Madeleine Justus. Mary’s own school-age children were some of the first students at Arbor. Mary led Arbor from 1993-2013 when she stepped down as Head of School. Her oldest son Sean, a credentialed Montessori teacher and administrator himself, took over as Head of School. He continued in that role until January 2022, when the current Head of School Nicole Champoux took the helm. 

Arbor has grown from just 8 Elementary students in 1993  and now serves up to 175 students from 16 months old through 6th grade! 

At Arbor, we have a beautifully diverse community. We believe that each family is unique and that every family is welcome here. It’s important that children have a chance to celebrate their own families, including everything from culture and heritage to structure and members, and beyond. It’s also just as important for children to learn about all types of families, and come to understand that the only universal definition of a family is love. When we celebrate ourselves and others, we are creating an inclusive, welcoming community.