In the late nineteenth century the De Forest family acquired considerable property along the western shore of Cold Spring Harbor where the natural barrier beach, the Sand Spit, separates the inner and outer harbors. On the larger, sloping wooded northern parcel, Henry Grant De Forest built a house he named ‘“Nethermuir,” Nethermuir,' after a village in Scotland. His son, Henry Wheeler De Forest, increased the acreage and extensively renovated the house c. 1900. The smaller, southern parcel contained a historic shingled farmhouse named “Airslie,” which became his daughter Julia Mary’s estate until her death in 1910, when it reverted to her brother.
Frederick Law Olmsted, Jr., of Olmsted Brothers, enhanced the landscape beginning in 1906, introducing substantial regrading for well-drained road connections on the steep terrain, rearranging trees to bolster privacy and view corridors,; and creating gardens, lawns, and ancillary structures. An elongated multi-acre oblong had already been carved into the slope west of Nethermuir, divided into perennial beds. With Edward Clark Whiting, between 1907 and 1909 Olmsted designed ten- to twelve-foot-tall ashlar enclosing walls for this space, against which he draped vines or espaliered plants, filling the foreground with flowering shrubs and small trees. At each end elevated structures were added to overlook the garden. Olmsted tiered the interior space with lower dry-laid walls with plant pockets to visually soften the stone. Axial paths bisected herbaceous planting beds.
Olmsted and Whiting additionally shaped passages of scenery throughout both properties, interspersing open rolling lawn with shadowy copses of conifers or deciduous trees, underplanted with kalmias, azaleas, and other flowering shrubs. At Airslie, they developed a piazza and intimate garden. Henry De Forest continued to improve his properties with Olmsted supervision until his death in 1938, building more stone walls, regrading roads, and rearranging plant groupings.
Cold Spring Harbor Laboratory (CSHL) acquired Airslie and the stables in 1943. By the 1990s, their holdings included the Sand Spit and grounds of Nethermuir (the house no longer extant). Over the next decades, the former formal garden was incorporated, now subdivided into parcels with garden structures converted into residences. A drive now bisects the lawns. Diverse tree groupings, some mature remnants from the Olmsted designs for Nethermuir, still grace the campus. The Cold Spring Harbor Laboratory Historic District was listed in the National Register of Historic Places in 1994.