Epidemiology is a holistic investigation of factors affecting the health and illness of populations. The goal of this study was to assess different risk factors related to West Nile virus (WNV) in New York State (NYS). WNV first appeared here in 1999 and is now considered endemic in NYS. The factors that play a role in the perpetuation of the virus are not fully understood. We studied a known host, a possible vector, and two other possible hosts. Our study encompassed the risk factors of crows in Tompkins County, the role of non-Culex species mosquitoes in Tompkins, Nassau, and Suffolk Counties, the possible component of dairy cattle in the New York City Watershed (Delaware County), and the element of mesopredators in Nassau and Suffolk Counties.