Miller has been a resident of Essex since 1982, where he served as the town's first selectman since 2003. He currently chairs the Middlesex County Revitalization, helping to provide long-term low interest loans to expanding businesses.

Miller also worked for historical and environmental preservation in Essex by serving on the Essex Conversation and Inland Wetlands and Watercourses Commissions. Before serving as first selectman, Miller was the director of the Bushy Hill Nature Center in the Ivoryton section of Essex. He founded a natural history day camp, named by Child Magazine as one of the nation’s “top ten youth programs.”