Bartonella species are emerging bacterial zoonoses. Two properties in Sonoma County, California were chosen where the occupants have past documented exposure to tick-borne disease. In an effort to examine the infection and coinfection prevalence of Bartonella species, Borrelia burgdorferi, and Anaplasma phagocytophilum in rodents and ectoparasites on these properties, questing ticks were collected biweekly for a year from ecotone and leaf litter habitats by flagging and rodents were trapped biweekly for one year. Forty-three rodents were captured consisting of 22 Peromyscus maniculatus, 8 Peromyscus boylii, 5 Peromyscus truei, and 8 Neotoma fuscipes. From each of these animals, an ear punch biopsy was taken for Borrelia culture; they were then bled and checked for ectoparasites. Ectoparasites were cultured for Borrelia and Bartonella infection. One-hundred-and-four live Ixodes pacificus adults have been culture tested for Borrelia and Bartonella infection. None of the rodent ear punch biopsy or tick cultures was culture positive for Borrelia burgdorferi. Fifty-seven (54%) tick samples were presumptively culture positive for Bartonella infection and are currently awaiting PCR confirmation. That we know of, this is the first attempt to culture Bartonella from ticks and the first one to examine links between Bartonella, B. burgdorferi, and A. phagocytophilum infectivities in rodents and questing ticks. Furthermore, laboratory transmission experiments with Peromyscus mice, rodent-borne Bartonella, and two species of hard ticks (Ixodes pacificus and Dermacentor occidentalis) are being performed to further elucidate the question, “Are ticks vectors of Bartonella?”