West Nile virus (WNV) was first detected in the United States during an outbreak in New York City in 1999, with 62 human cases including seven deaths. Since then, WNV has been declared endemic in the US and in 2012 the CDC reported 5,674 human cases, including 268 deaths, from 49 states. As an emerging disease, WNV has become a serious public health problem and has proven extremely difficult to prevent and control due to its transmission by several species of mosquitoes and spread by resident and migratory birds. We propose a deterministic model by including interactions among mosquitoes, birds, and humans to study the local transmission dynamics of WNV. To validate the model, it is used to simulate the human WNV data from New York, Florida, and Texas as reported to the CDC. These simulations demonstrate that the epidemic of WNV in these states has not reached its equilibrium yet and may be expected to get worse with current control strategies. Using mathematical and numerical analyses of the model, we will provide a better understanding of the transmission dynamics of WNV and explore control measures for the local outbreaks of the disease.