Elk Rock, a steep bluff on the lower Willamette River directly west of Elk Rock Island, became the property of Scottish grain exporter Peter Kerr (1862-1957) in the early 1900s. The 13-acre estate included six acres of cultivated English-style gardens that were designed in part by John C. Olmsted of the landscape architectural firm Olmsted Brothers of Brookline, Massachusetts.
Mr. Kerr passed away in 1957 and the estate was donated by his heirs to the Episcopal Diocese of Oregon with the agreement that the gardens would be open to the public. They were named the Elk Rock Gardens of the Bishop's Close. This garden and cliff-top estate are in stark contrast to the natural habitat that was given to the city by Peter Kerr in 1940. Elk Rock Island is located in the Willamette River and accessible from Spring Park on the east side of the river in the City of Milwaukie.
In 1955, the Kerr family gave the City of Portland a 3-acre parcel south of their estate with the stipulation that the property "shall be used solely as a public park . . ." This natural habitat contains a substantial portion of a 1,200-foot-long railroad tunnel that had been built through Elk Rock.