The philosophy of BOND, founded by California vintner H. William Harlan, is to offer wines from vineyards that highlight very specific sites in Napa Valley. William Harlan, owner of Harlan Estates noticed some vineyards usued for his flagship estate were distinct enough to be bottled on their own, as single vineyards. This inspired him to found Bond Estates. Today, five sites have been carefully selected to best express the richness of Cabernet Sauvignon. These five sites have been named "the grand crus of Napa" by Harlan. Each of the five BOND sites is quite small (between 7 and 11 acres in size), producing roughly 450 to 600 cases annually. While the company does not actually own the vineyards, BOND Estates does maintain total viticultural control over them, with the winegrowing directed by Bob Levy. The fruit is purchased under "evergreen contracts" which are renewned each year. BOND wines are produced with the aim to reflect the unique terroir from which they came. The lower-altitude Melbury vineyard, with its clay-based soils, produces elegant Cabernet Sauvignon wines with rich spice and violet fragrances. The Pluribus vineyard, planted at 1,100 to 1,300 feet above sea level on Spring Mountain is characterised by its volcanic bedrock and surrounding conifer forest, which lends a touch of cedar to the finished wines. The Quella vineyard, situated on a riverbed, is home to cobble and rock, along with tufa soils and produces very structured wines with a touch of salinity. The vines of the St. Eden vineyard stretch their roots into iron-rich, rocky soils at lower elevations of 145 to 188 feet, producing very precise wines with great acidity and concentrated flavours. And finaly, the Vecina vineyard is planted on terraced slopes of volcanic soil, producing beautifully layered wines with a high concentration of tannins. Since 2001, Mary Maher has been vineyard manager, and has introduced the use of biodynamic mulch in the BOND Estates vineyards. Irrigation has also gradually been phased out, which has resulted in riper, more mature tannins and flavour in the wines.