By spring 1890, the owners of Rancho Sausalito, Tamalpais Land & Water Co., were ready to start development of the Eastland, Millwood and Vicinity subdivision (part of Mill Valley). A railroad spur had been constructed to deliver potential buyers. M.M. O’Shaughnessy and his team of surveyors had prepared a plan of gently graded streets and pedestrian paths for access to hillside lots. The boundaries of lots near the railroad depot as well as larger blocks of land for development farther out had been established. Map No. 1 specified that subdivision properties would be offered at auction on Saturday May 31, 1890. The auction took place in what is now Old Mill Park beside the Old Mill which was “spruced up” for the occasion. Four morning ferries connecting to four special trains brought 3000 people to the auction. Free conveyance was offered to the property sites. Lunch was served at reasonable prices. More than 200 parcels, totaling about 200 acres were sold. Three speculators bought more than a dozen lots each. Most buyers intended to build on their property and live in Mill Valley, at least in the summers.
Mill Valley was born as a community planned by a single developer, the Tamalpais Land & Water Company.