More information on Ft Ross can be found here.
The Russian's venture was not as successful as hoped. They were not able to produce enough food to supply the colonies in Alaska. The native Alaskans they employed were more successful at their task. They were such good hunters that they almost managed to hunt the sea otters to extinction.
The fort was eventually sold to John Sutter who removed anything of value to Sutter's Fort in Sacramento. There followed a series of owners and the state acquired the property in 1906, just before the San Francisco earthquake. The fort was heavily damaged in the quake and most of the buildings had to be rebuilt.