Deer and elk vehicle collisions are a major safety concern for highways. While there are a number of methods which can be used to reduce collisions, the selection of the appropriate method is complicated by the fact that Washington is home to four subspecies of deer, in addition to elk and moose. Differences between the life history of the species and the types of habitat they occupy can lead to differences in what methods may be suitable for reducing vehicle-ungulate collisions. The Washington State Department of Transportation (WSDOT) maintains a deer kill database which contains information on where dead ungulates are removed from the state highways. This information is used along with site-specific information to determine what type of mitigation method may work the best to reduce the ungulate vehicle collisions.