A highlight of the park is the home of John Marsh , which was begun in 1853 and completed in 1856 , and which has been undergoing extensive renovation for several years . Marsh was the first non-Hispanic white settler to live in the county . The property encompassed by Marsh Creek State Park was part of Rancho Los Meganos , ( '' Los Meganos '' is a Spanish phrase meaning " sand dunes " ) , which Marsh acquired in 1838 . Initially , Marsh lived in a four-room adobe house which had been built on the property for him by local Miwok Indians . Marsh apparently got along well with the Miwoks and had even provided them with free medical care . In return , the tribesmen built the adobe house . After he married Abby Tuck in 1851 , he retained San Francisco architect Thomas Boyd to design a grand new mansion . Many of the features apparently were stipulated by Marsh himself . John 's wife , Abby , had selected the site for the house along Marsh Creek . The new Gothic Revival style house was three stories high and had an observation tower that rose into the air . Marsh built the tower so that he could see the approach of strangers from a great distance . Rustlers and marauders frequently came to his ranch to steal cattle or steal other valuables . However , the stone tower proved vulnerable to earthquakes . The original tower collapsed during the 1868 Hayward earthquake . It was rebuilt with wood , but the replacement collapsed again after the 1906 quake . Images from the Historical American Building Survey ( HABS ) collection in the Library of Congress shown here depict the differences in the two structures . This house is the earliest substantial building in Contra Costa County that was not built entirely of adobe
1868 Hayward earthquake
1868 Hayward earthquake
Marsh Creek State Park (California)