Located in Modesto, California, Atherton & Associates, LLP was founded more than 50 years ago. The firm has seven partners and provides services to over 3,500 clients and employs approximately 40 individuals. As one of the largest CPA & consulting firms in the San Joaquin Valley, Atherton & Associates, LLP also has the ability and resources to tackle the most complex business situations. We enhanced those abilities in 2003 by joining the RSM US Alliance.