I follow trends closely in this neighborhood ( I live here, too!). As of this writing, 68 homes have sold year to date with a median price of $717,000 in San Anselmo. According to the Dept of Agriculture, the median household income in California in 2011 was $57,664. In Marin, it was $82,383. About 50% higher than the state median. San Anselmo Median income in 2011 was $110,592 which is even higher. So, I would say, yes, it is an upper middle class neighborhood.