Me. Charles E. Mowry, an original contributor to the Arboretum and one of the early Board Members, was a modern pioneer of the community whose large farmlands adjoined the Arboretum. Mr. Mowry added many lovely plants and trees to the acreage, and cared for sections of the property until his death in 1966.

A tradition of memorial tree planting began on Arbor Day 1965 by the Class of 1965 of Thomas Jefferson High School as well as by the students of other schools in Pleasant Hills. Contributions from individuals either for plantings or maintenance of the Arboretum have always been welcome.