Markham Regional Arboretum in Concord, California, is a 16-acre garden and parkland that has remained largely in a natural state while developing from a series of city land purchases. It began with a small parcel acquired in 1963 and expanded notably in 1966 when Ira and Bea "Bee" Markham sold their house and 12 acres, including gardens along Galindo Creek and more than 1,400 trees they had planted. Additional land in 1980 brought it to its present size, and in 1981 a supporting society helped shape its current form. Its importance lies in blending preserved natural landscape, earlier private gardens, and community stewardship.