The Shadelands Ranch house is the last remnant of a once larger ranch, which was significant for its historical association with agricultural development in Contra Costa County.

The house, designed by the firm of Eckers & Sells, is one of the best remaining examples of Colonial Revival architecture in Contra Costa County and the only major Colonial Revival house in the Walnut Creek area.

Hiram Penniman, builder of Shadelands, was one of the earliest pioneers in Ygnacio Valley, coming in 1852, and planting orchards of fruits and nuts. His sun-dried fruits, which were shipped to eastern markets, represented the first large-scale commercial orchard operation in Ygnacio Valley. His principal crops were prunes, peaches, apricots, pears, and almonds. Penniman was one of the founders of the Agricultural Society of Contra Costa County.

Extracted from the NRHP nomination.

The ranch is now home to the Shadelands Ranch Historical Museum.

The restrored tank house and worker's cabin were moved here from Walnut Creek's Cereghino Ranch in 1995.