The rapid spread of West Nile Virus (WNV) in the United States has emphasized public health officials concerns about emergent zoonotic diseases. As deer populations continually expand in neighborhoods and areas of significant human activity, Iowans are at an increased risk of several zoonotic infections. We propose a pilot study of over one thousand white-tailed deer (WTD) and several thousand mosquitoes 1) to determine exposure of WTD to WNV, 2) to investigate whether WTD serve as a competent, peri-domestic reservoir for WNV, and 3) to determine anthropophilic mosquitoes that serve as bridge vectors to humans. Serologic testing of deer sera, identification of mosquito host blood, and testing of mosquitoes by polymerase chain reaction will be performed to document risk of Iowans to potential WNV infection. We believe these results will lead to improved surveillance, prevention, and control methods of WNV infections in humans.