The Runnymede Sanctuary

The Runnymede Sanctuary

The Runnymede Sanctuary was established in 2013 by Diana S. Wister, a member of the Philadelphia-area Strawbridge family. Wister established the trust as a 501(c)(3) not only to operate a wildlife sanctuary at 304 Creek Road in Coatesville, Pennsylvania, but also to manage an endowment that sustains it. Trustees include Margaret Duriez and Redmond Stewart Strawbridge, both relatives, anchoring governance within the family. The foundation's investment strategy is heavily concentrated in private markets. Asset-class exposures include private equity buyouts, private real estate, and private debt. The portfolio skews almost entirely toward buyout strategies, with a smaller allocation to real estate and credit vehicles. The sanctuary itself represents a direct real asset — a land holding in Chester County that serves dual conservation and operational purposes. The foundation does not publicly disclose its fund commitments or direct co-investments. Operational scale remains modest. Related philanthropic structures orbit the entity: the Margaret Dorrance Strawbridge Foundation of Pennsylvania II provides grants to Runnymede Sanctuary, creating a conduit between sister family foundations. Diana S. Wister also maintains ties to the Garden Conservancy Society of Fellows, reflecting the conservation ethos that underpins the entity. What distinguishes Runnymede from generic family foundations is its intentional fusion of mission and portfolio — the sanctuary is both beneficiary and identity. Most small endowments default to public-market liquidity; Runnymede instead runs a nearly all-private portfolio, trusting illiquidity to fund a permanent conservation purpose. The 2013 trust structure layers a Dtd 8/5/2013 instrument beneath the operating foundation, creating a legacy architecture where the wildlife mission and the private-investment engine are legally inseparable.